Power saving operation for a wireless device

ABSTRACT

A wireless device comprises one or more processors and memory storing instructions that, when executed by the one or more processors, cause the wireless device to: in response to a timer, for switching physical downlink control channel (PDCCH) monitoring from a first search space group (SSG) of a bandwidth part (BWP) to a second SSG of the BWP, expiring in a slot within a time duration for skipping PDCCH monitoring on the BWP, start to monitor PDCCH on the second SSG no earlier than an expiration of the time duration.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of International Application No.PCT/US2022/019749, filed Mar. 10, 2022, which claims the benefit of U.S.Provisional Application No. 63/159,202, filed Mar. 10, 2021, all ofwhich are hereby incorporated by reference in their entireties.

BRIEF DESCRIPTION OF THE DRAWINGS

Examples of several of the various embodiments of the present disclosureare described herein with reference to the drawings.

FIG. 1A and FIG. 1B illustrate example mobile communication networks inwhich embodiments of the present disclosure may be implemented.

FIG. 2A and FIG. 2B respectively illustrate a New Radio (NR) user planeand control plane protocol stack.

FIG. 3 illustrates an example of services provided between protocollayers of the NR user plane protocol stack of FIG. 2A.

FIG. 4A illustrates an example downlink data flow through the NR userplane protocol stack of FIG. 2A.

FIG. 4B illustrates an example format of a MAC subheader in a MAC PDU.

FIG. 5A and FIG. 5B respectively illustrate a mapping between logicalchannels, transport channels, and physical channels for the downlink anduplink.

FIG. 6 is an example diagram showing RRC state transitions of a UE.

FIG. 7 illustrates an example configuration of an NR frame into whichOFDM symbols are grouped.

FIG. 8 illustrates an example configuration of a slot in the time andfrequency domain for an NR carrier.

FIG. 9 illustrates an example of bandwidth adaptation using threeconfigured BWPs for an NR carrier.

FIG. 10A illustrates three carrier aggregation configurations with twocomponent carriers.

FIG. 10B illustrates an example of how aggregated cells may beconfigured into one or more PUCCH groups.

FIG. 11A illustrates an example of an SS/PBCH block structure andlocation.

FIG. 11B illustrates an example of CSI-RSs that are mapped in the timeand frequency domains.

FIG. 12A and FIG. 12B respectively illustrate examples of three downlinkand uplink beam management procedures.

FIG. 13A, FIG. 13B, and FIG. 13C respectively illustrate a four-stepcontention-based random access procedure, a two-step contention-freerandom access procedure, and another two-step random access procedure.

FIG. 14A illustrates an example of CORESET configurations for abandwidth part.

FIG. 14B illustrates an example of a CCE-to-REG mapping for DCItransmission on a CORESET and PDCCH processing.

FIG. 15 illustrates an example of a wireless device in communicationwith a base station.

FIG. 16A, FIG. 16B, FIG. 16C, and FIG. 16D illustrate example structuresfor uplink and downlink transmission.

FIG. 17A, FIG. 17B, and FIG. 17C show examples of MAC subheaders.

FIG. 18A shows an example of a DL MAC PDU.

FIG. 18B shows an example of an UL MAC PDU.

FIG. 19 shows an example of multiple LCIDs of downlink.

FIG. 20 shows an example of multiple LCIDs of uplink.

FIG. 21A and FIG. 21B show examples of SCell activation/deactivation MACCE formats, according to some embodiments.

FIG. 22A and FIG. 22B show examples of DRX configurations, according tosome embodiments.

FIG. 23 shows an example of BWP activation/deactivation on a cell,according to some embodiments.

FIG. 24 shows examples of various DCI formats, according to someembodiments.

FIG. 25 shows an example of dormancy configurations of a cell, accordingto some embodiments.

FIG. 26 shows an example of RRC configuration of control resource sets,according to some embodiments.

FIG. 27 shows an example of RRC configuration of a search space,according to some embodiments.

FIG. 28A and FIG. 28B show examples of search space group switchingoperation, according to some embodiments.

FIG. 29 shows an example of PDCCH skipping operation, according to someembodiments.

FIG. 30 shows an example of power saving based on PDCCH skipping andsearch space group switching, according to some embodiments.

FIG. 31 shows an example of power saving based on PDCCH skipping andsearch space group switching, according to some embodiments.

FIG. 32 shows an example of power saving based on PDCCH skipping andsearch space group switching, according to some embodiments.

FIG. 33 shows an example of power saving based on PDCCH skipping andsearch space group switching, according to some embodiments.

FIG. 34 shows an example of power saving based on PDCCH skipping andsearch space group switching, according to some embodiments.

FIG. 35 shows an example flowchart for achieving power saving based onPDCCH skipping and search space group switching, according to someembodiments.

FIG. 36 shows an example of power saving based on PDCCH skipping andsearch space group switching, according to some embodiments.

FIG. 37 shows an example of time value indications of PDCCH skipping,according to some embodiments.

FIG. 38 shows an example of power saving based on PDCCH skipping andsearch space group switching, according to some embodiments.

DETAILED DESCRIPTION

In the present disclosure, various embodiments are presented as examplesof how the disclosed techniques may be implemented and/or how thedisclosed techniques may be practiced in environments and scenarios. Itwill be apparent to persons skilled in the relevant art that variouschanges in form and detail can be made therein without departing fromthe scope. In fact, after reading the description, it will be apparentto one skilled in the relevant art how to implement alternativeembodiments. The present embodiments should not be limited by any of thedescribed exemplary embodiments. The embodiments of the presentdisclosure will be described with reference to the accompanyingdrawings. Limitations, features, and/or elements from the disclosedexample embodiments may be combined to create further embodiments withinthe scope of the disclosure. Any figures which highlight thefunctionality and advantages, are presented for example purposes only.The disclosed architecture is sufficiently flexible and configurable,such that it may be utilized in ways other than that shown. For example,the actions listed in any flowchart may be re-ordered or only optionallyused in some embodiments.

Embodiments may be configured to operate as needed. The disclosedmechanism may be performed when certain criteria are met, for example,in a wireless device, a base station, a radio environment, a network, acombination of the above, and/or the like. Example criteria may bebased, at least in part, on for example, wireless device or network nodeconfigurations, traffic load, initial system set up, packet sizes,traffic characteristics, a combination of the above, and/or the like.When the one or more criteria are met, various example embodiments maybe applied. Therefore, it may be possible to implement exampleembodiments that selectively implement disclosed protocols.

A base station may communicate with a mix of wireless devices. Wirelessdevices and/or base stations may support multiple technologies, and/ormultiple releases of the same technology. Wireless devices may have somespecific capability(ies) depending on wireless device category and/orcapability(ies). When this disclosure refers to a base stationcommunicating with a plurality of wireless devices, this disclosure mayrefer to a subset of the total wireless devices in a coverage area. Thisdisclosure may refer to, for example, a plurality of wireless devices ofa given LTE or 5G release with a given capability and in a given sectorof the base station. The plurality of wireless devices in thisdisclosure may refer to a selected plurality of wireless devices, and/ora subset of total wireless devices in a coverage area which performaccording to disclosed methods, and/or the like. There may be aplurality of base stations or a plurality of wireless devices in acoverage area that may not comply with the disclosed methods, forexample, those wireless devices or base stations may perform based onolder releases of LTE or 5G technology.

In this disclosure, “a” and “an” and similar phrases are to beinterpreted as “at least one” and “one or more.” Similarly, any termthat ends with the suffix “(s)” is to be interpreted as “at least one”and “one or more.” In this disclosure, the term “may” is to beinterpreted as “may, for example.” In other words, the term “may” isindicative that the phrase following the term “may” is an example of oneof a multitude of suitable possibilities that may, or may not, beemployed by one or more of the various embodiments. The terms“comprises” and “consists of”, as used herein, enumerate one or morecomponents of the element being described. The term “comprises” isinterchangeable with “includes” and does not exclude unenumeratedcomponents from being included in the element being described. Bycontrast, “consists of” provides a complete enumeration of the one ormore components of the element being described. The term “based on”, asused herein, should be interpreted as “based at least in part on” ratherthan, for example, “based solely on”. The term “and/or” as used hereinrepresents any possible combination of enumerated elements. For example,“A, B, and/or C” may represent A; B; C; A and B; A and C; B and C; or A,B, and C.

If A and B are sets and every element of A is an element of B, A iscalled a subset of B. In this specification, only non-empty sets andsubsets are considered. For example, possible subsets of B={cell1,cell2} are: {cell1}, {cell2}, and {cell1, cell2}. The phrase “based on”(or equally “based at least on”) is indicative that the phrase followingthe term “based on” is an example of one of a multitude of suitablepossibilities that may, or may not, be employed to one or more of thevarious embodiments. The phrase “in response to” (or equally “inresponse at least to”) is indicative that the phrase following thephrase “in response to” is an example of one of a multitude of suitablepossibilities that may, or may not, be employed to one or more of thevarious embodiments. The phrase “depending on” (or equally “depending atleast to”) is indicative that the phrase following the phrase “dependingon” is an example of one of a multitude of suitable possibilities thatmay, or may not, be employed to one or more of the various embodiments.The phrase “employing/using” (or equally “employing/using at least”) isindicative that the phrase following the phrase “employing/using” is anexample of one of a multitude of suitable possibilities that may, or maynot, be employed to one or more of the various embodiments.

The term configured may relate to the capacity of a device whether thedevice is in an operational or non-operational state. Configured mayrefer to specific settings in a device that effect the operationalcharacteristics of the device whether the device is in an operational ornon-operational state. In other words, the hardware, software, firmware,registers, memory values, and/or the like may be “configured” within adevice, whether the device is in an operational or nonoperational state,to provide the device with specific characteristics. Terms such as “acontrol message to cause in a device” may mean that a control messagehas parameters that may be used to configure specific characteristics ormay be used to implement certain actions in the device, whether thedevice is in an operational or non-operational state.

In this disclosure, parameters (or equally called, fields, orInformation elements: IEs) may comprise one or more information objects,and an information object may comprise one or more other objects. Forexample, if parameter (IE) N comprises parameter (IE) M, and parameter(IE) M comprises parameter (IE) K, and parameter (IE) K comprisesparameter (information element) J. Then, for example, N comprises K, andN comprises J. In an example embodiment, when one or more messagescomprise a plurality of parameters, it implies that a parameter in theplurality of parameters is in at least one of the one or more messages,but does not have to be in each of the one or more messages.

Many features presented are described as being optional through the useof “may” or the use of parentheses. For the sake of brevity andlegibility, the present disclosure does not explicitly recite each andevery permutation that may be obtained by choosing from the set ofoptional features. The present disclosure is to be interpreted asexplicitly disclosing all such permutations. For example, a systemdescribed as having three optional features may be embodied in sevenways, namely with just one of the three possible features, with any twoof the three possible features or with three of the three possiblefeatures.

Many of the elements described in the disclosed embodiments may beimplemented as modules. A module is defined here as an element thatperforms a defined function and has a defined interface to otherelements. The modules described in this disclosure may be implemented inhardware, software in combination with hardware, firmware, wetware (e.g.hardware with a biological element) or a combination thereof, which maybe behaviorally equivalent. For example, modules may be implemented as asoftware routine written in a computer language configured to beexecuted by a hardware machine (such as C, C++, Fortran, Java, Basic,Matlab or the like) or a modeling/simulation program such as Simulink,Stateflow, GNU Octave, or LabVIEWMathScript. It may be possible toimplement modules using physical hardware that incorporates discrete orprogrammable analog, digital and/or quantum hardware. Examples ofprogrammable hardware comprise: computers, microcontrollers,microprocessors, application-specific integrated circuits (ASICs); fieldprogrammable gate arrays (FPGAs); and complex programmable logic devices(CPLDs). Computers, microcontrollers and microprocessors are programmedusing languages such as assembly, C, C++ or the like. FPGAs, ASICs andCPLDs are often programmed using hardware description languages (HDL)such as VHSIC hardware description language (VHDL) or Verilog thatconfigure connections between internal hardware modules with lesserfunctionality on a programmable device. The mentioned technologies areoften used in combination to achieve the result of a functional module.

FIG. 1A illustrates an example of a mobile communication network 100 inwhich embodiments of the present disclosure may be implemented. Themobile communication network 100 may be, for example, a public landmobile network (PLMN) run by a network operator. As illustrated in FIG.1A, the mobile communication network 100 includes a core network (CN)102, a radio access network (RAN) 104, and a wireless device 106.

The CN 102 may provide the wireless device 106 with an interlace to oneor more data networks (DNs), such as public DNs (e.g., the Internet),private DNs, and/or intra-operator DNs. As part of the interfacefunctionality, the CN 102 may set up end-to-end connections between thewireless device 106 and the one or more DNs, authenticate the wirelessdevice 106, and provide charging functionality.

The RAN 104 may connect the CN 102 to the wireless device 106 throughradio communications over an air interface. As part of the radiocommunications, the RAN 104 may provide scheduling, radio resourcemanagement, and retransmission protocols. The communication directionfrom the RAN 104 to the wireless device 106 over the air interface isknown as the downlink and the communication direction from the wirelessdevice 106 to the RAN 104 over the air interlace is known as the uplink.Downlink transmissions may be separated from uplink transmissions usingfrequency division duplexing (FDD), time-division duplexing (TDD),and/or some combination of the two duplexing techniques.

The term wireless device may be used throughout this disclosure to referto and encompass any mobile device or fixed (non-mobile) device forwhich wireless communication is needed or usable. For example, awireless device may be a telephone, smart phone, tablet, computer,laptop, sensor, meter, wearable device, Internet of Things (I) device,vehicle road side unit (RSU), relay node, automobile, and/or anycombination thereof. The term wireless device encompasses otherterminology, including user equipment (UE), user terminal (UT), accessterminal (AT), mobile station, handset, wireless transmit and receiveunit (WTRU), and/or wireless communication device.

The RAN 104 may include one or more base stations (not shown). The termbase station may be used throughout this disclosure to refer to andencompass a Node B (associated with UMTS and/or 3G standards), anEvolved Node B (eNB, associated with E-UTRA and/or 4G standards), aremote radio head (RRH), a baseband processing unit coupled to one ormore RRHs, a repeater node or relay node used to extend the coveragearea of a donor node, a Next Generation Evolved Node B (ng-eNB), aGeneration Node B (gNB, associated with NR and/or 5G standards), anaccess point (AP, associated with, for example, WiFi or any othersuitable wireless communication standard), and/or any combinationthereof. A base station may comprise at least one gNB Central Unit(gNB-CU) and at least one a gNB Distributed Unit (gNB-DU).

A base station included in the RAN 104 may include one or more sets ofantennas for communicating with the wireless device 106 over the airinterface. For example, one or more of the base stations may includethree sets of antennas to respectively control three cells (or sectors).The size of a cell may be determined by a range at which a receiver(e.g., a base station receiver) can successfully receive thetransmissions from a transmitter (e.g., a wireless device transmitter)operating in the cell. Together, the cells of the base stations mayprovide radio coverage to the wireless device 106 over a wide geographicarea to support wireless device mobility.

In addition to three-sector sites, other implementations of basestations are possible. For example, one or more of the base stations inthe RAN 104 may be implemented as a sectored site with more or less thanthree sectors. One or more of the base stations in the RAN 104 may beimplemented as an access point, as a baseband processing unit coupled toseveral remote radio heads (RRHs), and/or as a repeater or relay nodeused to extend the coverage area of a donor node. A baseband processingunit coupled to RRHs may be part of a centralized or cloud RANarchitecture, where the baseband processing unit may be eithercentralized in a pool of baseband processing units or virtualized. Arepeater node may amplify and rebroadcast a radio signal received from adonor node. A relay node may perform the same/similar functions as arepeater node but may decode the radio signal received from the donornode to remove noise before amplifying and rebroadcasting the radiosignal.

The RAN 104 may be deployed as a homogenous network of macrocell basestations that have similar antenna patterns and similar high-leveltransmit powers. The RAN 104 may be deployed as a heterogeneous network.In heterogeneous networks, small cell base stations may be used toprovide small coverage areas, for example, coverage areas that overlapwith the comparatively larger coverage areas provided by macrocell basestations. The small coverage areas may be provided in areas with highdata traffic (or so-called “hotspots”) or in areas with weak macrocellcoverage. Examples of small cell base stations include, in order ofdecreasing coverage area, microcell base stations, picocell basestations, and femtocell base stations or home base stations.

The Third-Generation Partnership Project (3GPP) was formed in 1998 toprovide global standardization of specifications for mobilecommunication networks similar to the mobile communication network 100in FIG. 1A. To date, 3GPP has produced specifications for threegenerations of mobile networks: a third generation (3G) network known asUniversal Mobile Telecommunications System (UMTS), a fourth generation(4G) network known as Long-Term Evolution (LTE), and a fifth generation(5G) network known as 5G System (5GS). Embodiments of the presentdisclosure are described with reference to the RAN of a 3GPP 5G network,referred to as next-generation RAN (NG-RAN). Embodiments may beapplicable to RANs of other mobile communication networks, such as theRAN 104 in FIG. 1A, the RANs of earlier 3G and 4G networks, and those offuture networks yet to be specified (e.g., a 3GPP 6G network). NG-RANimplements 5G radio access technology known as New Radio (NR) and may beprovisioned to implement 4G radio access technology or other radioaccess technologies, including non-3GPP radio access technologies.

FIG. 1B illustrates another example mobile communication network 150 inwhich embodiments of the present disclosure may be implemented. Mobilecommunication network 150 may be, for example, a PLMN run by a networkoperator. As illustrated in FIG. 1B, mobile communication network 150includes a 5G core network (5G-CN) 152, an NG-RAN 154, and UEs 156A and156B (collectively UEs 156). These components may be implemented andoperate in the same or similar manner as corresponding componentsdescribed with respect to FIG. 1A.

The 5G-CN 152 provides the UEs 156 with an interface to one or more DNs,such as public DNs (e.g., the Internet), private DNs, and/orintra-operator DNs. As part of the interface functionality, the 5G-CN152 may set up end-to-end connections between the UEs 156 and the one ormore DNs, authenticate the UEs 156, and provide charging functionality.Compared to the CN of a 3GPP 4G network, the basis of the 5G-CN 152 maybe a service-based architecture. This means that the architecture of thenodes making up the 5G-CN 152 may be defined as network functions thatoffer services via interfaces to other network functions. The networkfunctions of the 5G-CN 152 may be implemented in several ways, includingas network elements on dedicated or shared hardware, as softwareinstances running on dedicated or shared hardware, or as virtualizedfunctions instantiated on a platform (e.g., a cloud-based platform).

As illustrated in FIG. 1B, the 5G-CN 152 includes an Access and MobilityManagement Function (AMF) 158A and a User Plane Function (UPF) 158B,which are shown as one component AMF/UPF 158 in FIG. 1B for ease ofillustration. The UPF 158B may serve as a gateway between the NG-RAN 154and the one or more DNs. The UPF 158B may perform functions such aspacket routing and forwarding, packet inspection and user plane policyrule enforcement, traffic usage reporting, uplink classification tosupport routing of traffic flows to the one or more DNs, quality ofservice (QoS) handling for the user plane (e.g., packet filtering,gating, uplink/downlink rate enforcement, and uplink trafficverification), downlink packet buffering, and downlink data notificationtriggering. The UPF 158B may serve as an anchor point forintra-/inter-Radio Access Technology (RAT) mobility, an externalprotocol (or packet) data unit (PDU) session point of interconnect tothe one or more DNs, and/or a branching point to support a multi-homedPDU session. The UEs 156 may be configured to receive services through aPDU session, which is a logical connection between a UE and a DN.

The AMF 158A may perform functions such as Non-Access Stratum (NAS)signaling termination, NAS signaling security, Access Stratum (AS)security control, inter-ON node signaling for mobility between 3GPPaccess networks, idle mode UE reachability (e.g., control and executionof paging retransmission), registration area management, intra-systemand inter-system mobility support, access authentication, accessauthorization including checking of roaming rights, mobility managementcontrol (subscription and policies), network slicing support, and/orsession management function (SMF) selection. NAS may refer to thefunctionality operating between a CN and a UE, and AS may refer to thefunctionality operating between the UE and a RAN.

The 5G-CN 152 may include one or more additional network functions thatare not shown in FIG. 1B for the sake of clarity. For example, the 5G-CN152 may include one or more of a Session Management Function (SMF), anNR Repository Function (NRF), a Policy Control Function (PCF), a NetworkExposure Function (NEF), a Unified Data Management (UDM), an ApplicationFunction (AF), and/or an Authentication Server Function (AUSF).

The NG-RAN 154 may connect the 5G-CN 152 to the UEs 156 through radiocommunications over the air interface. The NG-RAN 154 may include one ormore gNBs, illustrated as gNB 160A and gNB 160B (collectively gNBs 160)and/or one or more ng-eNBs, illustrated as ng-eNB 162A and ng-eNB 162B(collectively ng-eNBs 162). The gNBs 160 and ng-eNBs 162 may be moregenerically referred to as base stations. The gNBs 160 and ng-eNBs 162may include one or more sets of antennas for communicating with the UEs156 over an air interface. For example, one or more of the gNBs 160and/or one or more of the ng-eNBs 162 may include three sets of antennasto respectively control three cells (or sectors). Together, the cells ofthe gNBs 160 and the ng-eNBs 162 may provide radio coverage to the UEs156 over a wide geographic area to support UE mobility.

As shown in FIG. 1B, the gNBs 160 and/or the ng-eNBs 162 may beconnected to the 5G-CN 152 by means of an NG interface and to other basestations by an Xn interface. The NG and Xn interfaces may be establishedusing direct physical connections and/or indirect connections over anunderlying transport network, such as an internet protocol (IP)transport network. The gNBs 160 and/or the ng-eNBs 162 may be connectedto the UEs 156 by means of a Uu interface. For example, as illustratedin FIG. 1B, gNB 160A may be connected to the UE 156A by means of a Uuinterface. The NG, Xn, and Uu interfaces are associated with a protocolstack. The protocol stacks associated with the interfaces may be used bythe network elements in FIG. 1B to exchange data and signaling messagesand may include two planes: a user plane and a control plane. The userplane may handle data of interest to a user. The control plane mayhandle signaling messages of interest to the network elements.

The gNBs 160 and/or the ng-eNBs 162 may be connected to one or moreAMF/UPF functions of the 5G-CN 152, such as the AMF/UPF 158, by means ofone or more NG interfaces. For example, the gNB 160A may be connected tothe UPF 158B of the AMF/UPF 158 by means of an NG-User plane (NG-U)interface. The NG-U interface may provide delivery (e.g., non-guaranteeddelivery) of user plane PDUs between the gNB 160A and the UPF 158B. ThegNB 160A may be connected to the AMF 158A by means of an NG-Controlplane (NG-C) interface. The NG-C interface may provide, for example, NGinterface management, UE context management, UE mobility management,transport of NAS messages, paging, PDU session management, andconfiguration transfer and/or warning message transmission.

The gNBs 160 may provide NR user plane and control plane protocolterminations towards the UEs 156 over the Uu interface. For example, thegNB 160A may provide NR user plane and control plane protocolterminations toward the UE 156A over a Uu interface associated with afirst protocol stack. The ng-eNBs 162 may provide Evolved UMTSTerrestrial Radio Access (E-UTRA) user plane and control plane protocolterminations towards the UEs 156 over a Uu interface, where E-UTRArefers to the 3GPP 4G radio-access technology. For example, the ng-eNB162B may provide E-UTRA user plane and control plane protocolterminations towards the UE 156B over a Uu interface associated with asecond protocol stack.

The 5G-CN 152 was described as being configured to handle NR and 4Gradio accesses. It will be appreciated by one of ordinary skill in theart that it may be possible for NR to connect to a 4G core network in amode known as “non-standalone operation.” In non-standalone operation, a4G core network is used to provide (or at least support) control-planefunctionality (e.g., initial access, mobility, and paging). Althoughonly one AMF/UPF 158 is shown in FIG. 1B, one gNB or ng-eNB may beconnected to multiple AMF/UPF nodes to provide redundancy and/or to loadshare across the multiple AMF/UPF nodes.

As discussed, an interface (e.g., Uu, Xn, and NG interlaces) between thenetwork elements in FIG. 1B may be associated with a protocol stack thatthe network elements use to exchange data and signaling messages. Aprotocol stack may include two planes: a user plane and a control plane.The user plane may handle data of interest to a user, and the controlplane may handle signaling messages of interest to the network elements.

FIG. 2A and FIG. 2B respectively illustrate examples of NR user planeand NR control plane protocol stacks for the Uu interlace that liesbetween a UE 210 and a gNB 220. The protocol stacks illustrated in FIG.2A and FIG. 2B may be the same or similar to those used for the Uuinterlace between, for example, the UE 156A and the gNB 160A shown inFIG. 1B.

FIG. 2A illustrates a NR user plane protocol stack comprising fivelayers implemented in the UE 210 and the gNB 220. At the bottom of theprotocol stack, physical layers (PHYs) 211 and 221 may provide transportservices to the higher layers of the protocol stack and may correspondto layer 1 of the Open Systems Interconnection (OSI) model. The nextfour protocols above PHYs 211 and 221 comprise media access controllayers (MACs) 212 and 222, radio link control layers (RLCs) 213 and 223,packet data convergence protocol layers (PDCPs) 214 and 224, and servicedata application protocol layers (SDAPs) 215 and 225. Together, thesefour protocols may make up layer 2, or the data link layer, of the OSImodel.

FIG. 3 illustrates an example of services provided between protocollayers of the NR user plane protocol stack. Starting from the top ofFIG. 2A and FIG. 3 , the SDAPs 215 and 225 may perform QoS flowhandling. The UE 210 may receive services through a PDU session, whichmay be a logical connection between the UE 210 and a DN. The PDU sessionmay have one or more QoS flows. A UPF of a CN (e.g., the UPF 158B) maymap IP packets to the one or more QoS flows of the PDU session based onQoS requirements (e.g., in terms of delay, data rate, and/or errorrate).

The SDAPs 215 and 225 may perform mapping/de-mapping between the one ormore QoS flows and one or more data radio bearers. Themapping/de-mapping between the QoS flows and the data radio bearers maybe determined by the SDAP 225 at the gNB 220. The SDAP 215 at the UE 210may be informed of the mapping between the QoS flows and the data radiobearers through reflective mapping or control signaling received fromthe gNB 220. For reflective mapping, the SDAP 225 at the gNB 220 maymark the downlink packets with a QoS flow indicator (QFI), which may beobserved by the SDAP 215 at the UE 210 to determine themapping/de-mapping between the QoS flows and the data radio bearers.

The PDCPs 214 and 224 may perform header compression/decompression toreduce the amount of data that needs to be transmitted over the airinterface, ciphering/deciphering to prevent unauthorized decoding ofdata transmitted over the air interface, and integrity protection (toensure control messages originate from intended sources. The PDCPs 214and 224 may perform retransmissions of undelivered packets, in-sequencedelivery and reordering of packets, and removal of packets received induplicate due to, for example, an intra-gNB handover. The PDCPs 214 and224 may perform packet duplication to improve the likelihood of thepacket being received and, at the receiver, remove any duplicatepackets. Packet duplication may be useful for services that require highreliability.

Although not shown in FIG. 3 , PDCPs 214 and 224 may performmapping/de-mapping between a split radio bearer and RLC channels in adual connectivity scenario. Dual connectivity is a technique that allowsa UE to connect to two cells or, more generally, two cell groups: amaster cell group (MCG) and a secondary cell group (SCG). A split beareris when a single radio bearer, such as one of the radio bearers providedby the PDCPs 214 and 224 as a service to the SDAPs 215 and 225, ishandled by cell groups in dual connectivity. The PDCPs 214 and 224 maymap/de-map the split radio bearer between RLC channels belonging to cellgroups.

The RLCs 213 and 223 may perform segmentation, retransmission throughAutomatic Repeat Request (ARQ), and removal of duplicate data unitsreceived from MACs 212 and 222, respectively. The RLCs 213 and 223 maysupport three transmission modes: transparent mode (TM); unacknowledgedmode (UM); and acknowledged mode (AM). Based on the transmission mode anRLC is operating, the RLC may perform one or more of the notedfunctions. The RLC configuration may be per logical channel with nodependency on numerologies and/or Transmission Time Interval (TTI)durations. As shown in FIG. 3 , the RLCs 213 and 223 may provide RLCchannels as a service to PDCPs 214 and 224, respectively.

The MACs 212 and 222 may perform multiplexing/demultiplexing of logicalchannels and/or mapping between logical channels and transport channels.The multiplexing/demultiplexing may include multiplexing/demultiplexingof data units, belonging to the one or more logical channels, into/fromTransport Blocks (TBs) delivered to/from the PHYs 211 and 221. The MAC222 may be configured to perform scheduling, scheduling informationreporting, and priority handling between UEs by means of dynamicscheduling. Scheduling may be performed in the gNB 220 (at the MAC 222)for downlink and uplink. The MACs 212 and 222 may be configured toperform error correction through Hybrid Automatic Repeat Request (HARQ)(e.g., one HARQ entity per carrier in case of Carrier Aggregation (CA)),priority handling between logical channels of the UE 210 by means oflogical channel prioritization, and/or padding. The MACs 212 and 222 maysupport one or more numerologies and/or transmission timings. In anexample, mapping restrictions in a logical channel prioritization maycontrol which numerology and/or transmission timing a logical channelmay use. As shown in FIG. 3 , the MACs 212 and 222 may provide logicalchannels as a service to the RLCs 213 and 223.

The PHYs 211 and 221 may perform mapping of transport channels tophysical channels and digital and analog signal processing functions forsending and receiving information over the air interface. These digitaland analog signal processing functions may include, for example,coding/decoding and modulation/demodulation. The PHYs 211 and 221 mayperform multi-antenna mapping. As shown in FIG. 3 , the PHYs 211 and 221may provide one or more transport channels as a service to the MACs 212and 222.

FIG. 4A illustrates an example downlink data flow through the NR userplane protocol stack. FIG. 4A illustrates a downlink data flow of threeIP packets (n, n+1, and m) through the NR user plane protocol stack togenerate two TBs at the gNB 220. An uplink data flow through the NR userplane protocol stack may be similar to the downlink data flow depictedin FIG. 4A.

The downlink data flow of FIG. 4A begins when SDAP 225 receives thethree IP packets from one or more QoS flows and maps the three packetsto radio bearers. In FIG. 4A, the SDAP 225 maps IP packets n and n+1 toa first radio bearer 402 and maps IP packet m to a second radio bearer404. An SDAP header (labeled with an “H” in FIG. 4A) is added to an IPpacket. The data unit from/to a higher protocol layer is referred to asa service data unit (SDU) of the lower protocol layer and the data unitto/from a lower protocol layer is referred to as a protocol data unit(PDU) of the higher protocol layer. As shown in FIG. 4A, the data unitfrom the SDAP 225 is an SDU of lower protocol layer PDCP 224 and is aPDU of the SDAP 225.

The remaining protocol layers in FIG. 4A may perform their associatedfunctionality (e.g., with respect to FIG. 3 ), add correspondingheaders, and forward their respective outputs to the next lower layer.For example, the PDCP 224 may perform IP-header compression andciphering and forward its output to the RLC 223. The RLC 223 mayoptionally perform segmentation (e.g., as shown for IP packet m in FIG.4A) and forward its output to the MAC 222. The MAC 222 may multiplex anumber of RLC PDUs and may attach a MAC subheader to an RLC PDU to forma transport block. In NR, the MAC subheaders may be distributed acrossthe MAC PDU, as illustrated in FIG. 4A. In LTE, the MAC subheaders maybe entirely located at the beginning of the MAC PDU. The NR MAC PDUstructure may reduce processing time and associated latency because theMAC PDU subheaders may be computed before the full MAC PDU is assembled.

FIG. 4B illustrates an example format of a MAC subheader in a MAC PDU.The MAC subheader includes: an SDU length field for indicating thelength (e.g., in bytes) of the MAC SDU to which the MAC subheadercorresponds; a logical channel identifier (LCID) field for identifyingthe logical channel from which the MAC SDU originated to aid in thedemultiplexing process; a flag (F) for indicating the size of the SDUlength field; and a reserved bit (R) field for future use.

FIG. 4B further illustrates MAC control elements (CEs) inserted into theMAC PDU by a MAC, such as MAC 223 or MAC 222. For example, FIG. 4Billustrates two MAC CEs inserted into the MAC PDU. MAC CEs may beinserted at the beginning of a MAC PDU for downlink transmissions (asshown in FIG. 4B) and at the end of a MAC PDU for uplink transmissions.MAC CEs may be used for in-band control signaling. Example MAC CEsinclude: scheduling-related MAC CEs, such as buffer status reports andpower headroom reports; activation/deactivation MAC CEs, such as thosefor activation/deactivation of PDCP duplication detection, channel stateinformation (CSI) reporting, sounding reference signal (SRS)transmission, and prior configured components; discontinuous reception(DRX) related MAC CEs; timing advance MAC CEs; and random access relatedMAC CEs. A MAC CE may be preceded by a MAC subheader with a similarformat as described for MAC SDUs and may be identified with a reservedvalue in the LCID field that indicates the type of control informationincluded in the MAC CE.

Before describing the NR control plane protocol stack, logical channels,transport channels, and physical channels are first described as well asa mapping between the channel types. One or more of the channels may beused to carry out functions associated with the NR control planeprotocol stack described later below.

FIG. 5A and FIG. 5B illustrate, for downlink and uplink respectively, amapping between logical channels, transport channels, and physicalchannels. Information is passed through channels between the RLC, theMAC, and the PHY of the NR protocol stack. A logical channel may be usedbetween the RLC and the MAC and may be classified as a control channelthat carries control and configuration information in the NR controlplane or as a traffic channel that carries data in the NR user plane. Alogical channel may be classified as a dedicated logical channel that isdedicated to a specific UE or as a common logical channel that may beused by more than one UE. A logical channel may also be defined by thetype of information it carries. The set of logical channels defined byNR include, for example:

-   -   a paging control channel (PCCH) for carrying paging messages        used to page a UE whose location is not known to the network on        a cell level;    -   a broadcast control channel (BCCH) for carrying system        information messages in the form of a master information block        (MIB) and several system information blocks (SIBs), wherein the        system information messages may be used by the UEs to obtain        information about how a cell is configured and how to operate        within the cell;    -   a common control channel (CCCH) for carrying control messages        together with random access;    -   a dedicated control channel (DCCH) for carrying control messages        to/from a specific the UE to configure the UE; and    -   a dedicated traffic channel (DTCH) for carrying user data        to/from a specific the UE.

Transport channels are used between the MAC and PHY layers and may bedefined by how the information they carry is transmitted over the airinterface. The set of transport channels defined by NR include, forexample:

-   -   a paging channel (PCH) for carrying paging messages that        originated from the PCCH;    -   a broadcast channel (BCH) for carrying the MIB from the BCCH;    -   a downlink shared channel (DL-SCH) for carrying downlink data        and signaling messages, including the SIBs from the BCCH;    -   an uplink shared channel (UL-SCH) for carrying uplink data and        signaling messages; and    -   a random access channel (RACH) for allowing a UE to contact the        network without any prior scheduling.

The PHY may use physical channels to pass information between processinglevels of the PHY. A physical channel may have an associated set oftime-frequency resources for carrying the information of one or moretransport channels. The PHY may generate control information to supportthe low-level operation of the PHY and provide the control informationto the lower levels of the PHY via physical control channels, known asL1/L2 control channels. The set of physical channels and physicalcontrol channels defined by NR include, for example:

-   -   a physical broadcast channel (PBCH) for carrying the MIB from        the BCH;    -   a physical downlink shared channel (PDSCH) for carrying downlink        data and signaling messages from the DL-SCH, as well as paging        messages from the PCH;    -   a physical downlink control channel (PDCCH) for carrying        downlink control information (DCI), which may include downlink        scheduling commands, uplink scheduling grants, and uplink power        control commands;    -   a physical uplink shared channel (PUSCH) for carrying uplink        data and signaling messages from the UL-SCH and in some        instances uplink control information (UCI) as described below;    -   a physical uplink control channel (PUCCH) for carrying UCI,        which may include HARQ acknowledgments, channel quality        indicators (CQI), pre-coding matrix indicators (PMI), rank        indicators (RI), and scheduling requests (SR); and    -   a physical random access channel (PRACH) for random access.

Similar to the physical control channels, the physical layer generatesphysical signals to support the low-level operation of the physicallayer. As shown in FIG. 5A and FIG. 5B, the physical layer signalsdefined by NR include: primary synchronization signals (PSS), secondarysynchronization signals (SSS), channel state information referencesignals (CSI-RS), demodulation reference signals (DMRS), soundingreference signals (SRS), and phase-tracking reference signals (PT-RS).These physical layer signals will be described in greater detail below.

FIG. 2B illustrates an example NR control plane protocol stack. As shownin FIG. 2B, the NR control plane protocol stack may use the same/similarfirst four protocol layers as the example NR user plane protocol stack.These four protocol layers include the PHYs 211 and 221, the MACs 212and 222, the RLCs 213 and 223, and the PDCPs 214 and 224. Instead ofhaving the SDAPs 215 and 225 at the top of the stack as in the NR userplane protocol stack, the NR control plane stack has radio resourcecontrols (RRCs) 216 and 226 and NAS protocols 217 and 237 at the top ofthe NR control plane protocol stack.

The NAS protocols 217 and 237 may provide control plane functionalitybetween the UE 210 and the AMF 230 (e.g., the AMF 158A) or, moregenerally, between the UE 210 and the CN. The NAS protocols 217 and 237may provide control plane functionality between the UE 210 and the AMF230 via signaling messages, referred to as NAS messages. There is nodirect path between the UE 210 and the AMF 230 through which the NASmessages can be transported. The NAS messages may be transported usingthe AS of the Uu and NG interfaces. NAS protocols 217 and 237 mayprovide control plane functionality such as authentication, security,connection setup, mobility management, and session management.

The RRCs 216 and 226 may provide control plane functionality between theUE 210 and the gNB 220 or, more generally, between the UE 210 and theRAN. The RRCs 216 and 226 may provide control plane functionalitybetween the UE 210 and the gNB 220 via signaling messages, referred toas RRC messages. RRC messages may be transmitted between the UE 210 andthe RAN using signaling radio bearers and the same/similar PDCP, RLC,MAC, and PHY protocol layers. The MAC may multiplex control-plane anduser-plane data into the same transport block (TB). The RRCs 216 and 226may provide control plane functionality such as: broadcast of systeminformation related to AS and NAS; paging initiated by the CN or theRAN; establishment, maintenance and release of an RRC connection betweenthe UE 210 and the RAN; security functions including key management;establishment, configuration, maintenance and release of signaling radiobearers and data radio bearers; mobility functions; QoS managementfunctions; the UE measurement reporting and control of the reporting;detection of and recovery from radio link failure (RLF); and/or NASmessage transfer. As part of establishing an RRC connection, RRCs 216and 226 may establish an RRC context, which may involve configuringparameters for communication between the UE 210 and the RAN.

FIG. 6 is an example diagram showing RRC state transitions of a UE. TheUE may be the same or similar to the wireless device 106 depicted inFIG. 1A, the UE 210 depicted in FIG. 2A and FIG. 2B, or any otherwireless device described in the present disclosure. As illustrated inFIG. 6 , a UE may be in at least one of three RRC states: RRC connected602 (e.g., RRC_CONNECTED), RRC idle 604 (e.g., RRC_IDLE), and RRCinactive 606 (e.g., RRC_INACTIVE).

In RRC connected 602, the UE has an established RRC context and may haveat least one RRC connection with a base station. The base station may besimilar to one of the one or more base stations included in the RAN 104depicted in FIG. 1A, one of the gNBs 160 or ng-eNBs 162 depicted in FIG.1B, the gNB 220 depicted in FIG. 2A and FIG. 2B, or any other basestation described in the present disclosure. The base station with whichthe UE is connected may have the RRC context for the UE. The RRCcontext, referred to as the UE context, may comprise parameters forcommunication between the UE and the base station. These parameters mayinclude, for example: one or more AS contexts; one or more radio linkconfiguration parameters; bearer configuration information (e.g.,relating to a data radio bearer, signaling radio bearer, logicalchannel, QoS flow, and/or PDU session); security information; and/orPHY, MAC, RLC, PDCP, and/or SDAP layer configuration information. Whilein RRC connected 602, mobility of the UE may be managed by the RAN(e.g., the RAN 104 or the NG-RAN 154). The UE may measure the signallevels (e.g., reference signal levels) from a serving cell andneighboring cells and report these measurements to the base stationcurrently serving the UE. The UE's serving base station may request ahandover to a cell of one of the neighboring base stations based on thereported measurements. The RRC state may transition from RRC connected602 to RRC idle 604 through a connection release procedure 608 or to RRCinactive 606 through a connection inactivation procedure 610.

In RRC idle 604, an RRC context may not be established for the UE. InRRC idle 604, the UE may not have an RRC connection with the basestation. While in RRC idle 604, the UE may be in a sleep state for themajority of the time (e.g., to conserve battery power). The UE may wakeup periodically (e.g., once in every discontinuous reception cycle) tomonitor for paging messages from the RAN. Mobility of the UE may bemanaged by the UE through a procedure known as cell reselection. The RRCstate may transition from RRC idle 604 to RRC connected 602 through aconnection establishment procedure 612, which may involve a randomaccess procedure as discussed in greater detail below.

In RRC inactive 606, the RRC context previously established ismaintained in the UE and the base station. This allows for a fasttransition to RRC connected 602 with reduced signaling overhead ascompared to the transition from RRC idle 604 to RRC connected 602. Whilein RRC inactive 606, the UE may be in a sleep state and mobility of theUE may be managed by the UE through cell reselection. The RRC state maytransition from RRC inactive 606 to RRC connected 602 through aconnection resume procedure 614 or to RRC idle 604 though a connectionrelease procedure 616 that may be the same as or similar to connectionrelease procedure 608.

An RRC state may be associated with a mobility management mechanism. InRRC idle 604 and RRC inactive 606, mobility is managed by the UE throughcell reselection. The purpose of mobility management in RRC idle 604 andRRC inactive 606 is to allow the network to be able to notify the UE ofan event via a paging message without having to broadcast the pagingmessage over the entire mobile communications network. The mobilitymanagement mechanism used in RRC idle 604 and RRC inactive 606 may allowthe network to track the UE on a cell-group level so that the pagingmessage may be broadcast over the cells of the cell group that the UEcurrently resides within instead of the entire mobile communicationnetwork. The mobility management mechanisms for RRC idle 604 and RRCinactive 606 track the UE on a cell-group level. They may do so usingdifferent granularities of grouping. For example, there may be threelevels of cell-grouping granularity: individual cells; cells within aRAN area identified by a RAN area identifier (RAI); and cells within agroup of RAN areas, referred to as a tracking area and identified by atracking area identifier (TAI).

Tracking areas may be used to track the UE at the CN level. The CN(e.g., the CN 102 or the 5G-CN 152) may provide the UE with a list ofTAIs associated with a UE registration area. If the UE moves, throughcell reselection, to a cell associated with a TAI not included in thelist of TAIs associated with the UE registration area, the UE mayperform a registration update with the CN to allow the CN to update theUE's location and provide the UE with a new the UE registration area.

RAN areas may be used to track the UE at the RAN level. For a UE in RRCinactive 606 state, the UE may be assigned a RAN notification area. ARAN notification area may comprise one or more cell identities, a listof RAIs, or a list of TAIs. In an example, a base station may belong toone or more RAN notification areas. In an example, a cell may belong toone or more RAN notification areas. If the UE moves, through cellreselection, to a cell not included in the RAN notification areaassigned to the UE, the UE may perform a notification area update withthe RAN to update the UE's RAN notification area.

A base station storing an RRC context for a UE or a last serving basestation of the UE may be referred to as an anchor base station. Ananchor base station may maintain an RRC context for the UE at leastduring a period of time that the UE stays in a RAN notification area ofthe anchor base station and/or during a period of time that the UE staysin RRC inactive 606.

A gNB, such as gNBs 160 in FIG. 1B, may be split in two parts: a centralunit (gNB-CU), and one or more distributed units (gNB-DU). A gNB-CU maybe coupled to one or more gNB-DUs using an F1 interface. The gNB-CU maycomprise the RRC, the PDCP, and the SDAP. A gNB-DU may comprise the RLC,the MAC, and the PHY.

In NR, the physical signals and physical channels (discussed withrespect to FIG. 5A and FIG. 5B) may be mapped onto orthogonal frequencydivisional multiplexing (OFDM) symbols. OFDM is a multicarriercommunication scheme that transmits data over F orthogonal subcarriers(or tones). Before transmission, the data may be mapped to a series ofcomplex symbols (e.g., M-quadrature amplitude modulation (M-QAM) orM-phase shift keying (M-PSK) symbols), referred to as source symbols,and divided into F parallel symbol streams. The F parallel symbolstreams may be treated as though they are in the frequency domain andused as inputs to an Inverse Fast Fourier Transform (IFFT) block thattransforms them into the time domain. The IFFT block may take in Fsource symbols at a time, one from each of the F parallel symbolstreams, and use each source symbol to modulate the amplitude and phaseof one of F sinusoidal basis functions that correspond to the Forthogonal subcarriers. The output of the IFFT block may be Ftime-domain samples that represent the summation of the F orthogonalsubcarriers. The F time-domain samples may form a single OFDM symbol.After some processing (e.g., addition of a cyclic prefix) andup-conversion, an OFDM symbol provided by the IFFT block may betransmitted over the air interface on a carrier frequency. The Fparallel symbol streams may be mixed using an FFT block before beingprocessed by the IFFT block. This operation produces Discrete FourierTransform (DFT)-precoded OFDM symbols and may be used by UEs in theuplink to reduce the peak to average power ratio (PAPR). Inverseprocessing may be performed on the OFDM symbol at a receiver using anFFT block to recover the data mapped to the source symbols.

FIG. 7 illustrates an example configuration of an NR frame into whichOFDM symbols are grouped. An NR frame may be identified by a systemframe number (SFN). The SFN may repeat with a period of 1024 frames. Asillustrated, one NR frame may be 10 milliseconds (ms) in duration andmay include 10 subframes that are 1 ms in duration. A subframe may bedivided into slots that include, for example, 14 OFDM symbols per slot.

The duration of a slot may depend on the numerology used for the OFDMsymbols of the slot. In NR, a flexible numerology is supported toaccommodate different cell deployments (e.g., cells with carrierfrequencies below 1 GHz up to cells with carrier frequencies in themm-wave range). A numerology may be defined in terms of subcarrierspacing and cyclic prefix duration. For a numerology in NR, subcarrierspacings may be scaled up by powers of two from a baseline subcarrierspacing of 15 kHz, and cyclic prefix durations may be scaled down bypowers of two from a baseline cyclic prefix duration of 4.7 μs. Forexample, NR defines numerologies with the following subcarrierspacing/cyclic prefix duration combinations: 15 kHz/4.7 μs; 30 kHz/2.3μs; 60 kHz/1.2 μs; 120 kHz/0.59 μs; and 240 kHz/0.29 μs.

A slot may have a fixed number of OFDM symbols (e.g., 14 OFDM symbols).A numerology with a higher subcarrier spacing has a shorter slotduration and, correspondingly, more slots per subframe. FIG. 7illustrates this numerology-dependent slot duration andslots-per-subframe transmission structure (the numerology with asubcarrier spacing of 240 kHz is not shown in FIG. 7 for ease ofillustration). A subframe in NR may be used as a numerology-independenttime reference, while a slot may be used as the unit upon which uplinkand downlink transmissions are scheduled. To support low latency,scheduling in NR may be decoupled from the slot duration and start atany OFDM symbol and last for as many symbols as needed for atransmission. These partial slot transmissions may be referred to asmini-slot or subslot transmissions.

FIG. 8 illustrates an example configuration of a slot in the time andfrequency domain for an NR carrier. The slot includes resource elements(REs) and resource blocks (RBs). An RE is the smallest physical resourcein NR. An RE spans one OFDM symbol in the time domain by one subcarrierin the frequency domain as shown in FIG. 8 . An RB spans twelveconsecutive REs in the frequency domain as shown in FIG. 8 . An NRcarrier may be limited to a width of 275 RBs or 275×12=3300 subcarriers.Such a limitation, if used, may limit the NR carrier to 50, 100, 200,and 400 MHz for subcarrier spacings of 15, 30, 60, and 120 kHz,respectively, where the 400 MHz bandwidth may be set based on a 400 MHzper carrier bandwidth limit.

FIG. 8 illustrates a single numerology being used across the entirebandwidth of the NR carrier. In other example configurations, multiplenumerologies may be supported on the same carrier.

NR may support wide carrier bandwidths (e.g., up to 400 MHz for asubcarrier spacing of 120 kHz). Not all UEs may be able to receive thefull carrier bandwidth (e.g., due to hardware limitations). Also,receiving the full carrier bandwidth may be prohibitive in terms of UEpower consumption. In an example, to reduce power consumption and/or forother purposes, a UE may adapt the size of the UE's receive bandwidthbased on the amount of traffic the UE is scheduled to receive. This isreferred to as bandwidth adaptation.

NR defines bandwidth parts (BWPs) to support UEs not capable ofreceiving the full carrier bandwidth and to support bandwidthadaptation. In an example, a BWP may be defined by a subset ofcontiguous RBs on a carrier. A UE may be configured (e.g., via RRClayer) with one or more downlink BWPs and one or more uplink BWPs perserving cell (e.g., up to four downlink BWPs and up to four uplink BWPsper serving cell). At a given time, one or more of the configured BWPsfor a serving cell may be active. These one or more BWPs may be referredto as active BWPs of the serving cell. When a serving cell is configuredwith a secondary uplink carrier, the serving cell may have one or morefirst active BWPs in the uplink carrier and one or more second activeBWPs in the secondary uplink carrier.

For unpaired spectra, a downlink BWP from a set of configured downlinkBWPs may be linked with an uplink BWP from a set of configured uplinkBWPs if a downlink BWP index of the downlink BWP and an uplink BWP indexof the uplink BWP are the same. For unpaired spectra, a UE may expectthat a center frequency for a downlink BWP is the same as a centerfrequency for an uplink BWP.

For a downlink BWP in a set of configured downlink BWPs on a primarycell (PCell), a base station may configure a UE with one or more controlresource sets (CORESETs) for at least one search space. A search spaceis a set of locations in the time and frequency domains where the UE mayfind control information. The search space may be a UE-specific searchspace or a common search space (potentially usable by a plurality ofUEs). For example, a base station may configure a UE with a commonsearch space, on a PCell or on a primary secondary cell (PSCell), in anactive downlink BWP.

For an uplink BWP in a set of configured uplink BWPs, a BS may configurea UE with one or more resource sets for one or more PUCCH transmissions.A UE may receive downlink receptions (e.g., PDCCH or PDSCH) in adownlink BWP according to a configured numerology (e.g., subcarrierspacing and cyclic prefix duration) for the downlink BWP. The UE maytransmit uplink transmissions (e.g., PUCCH or PUSCH) in an uplink BWPaccording to a configured numerology (e.g., subcarrier spacing andcyclic prefix length for the uplink BWP).

One or more BWP indicator fields may be provided in Downlink ControlInformation (DCI). A value of a BWP indicator field may indicate whichBWP in a set of configured BWPs is an active downlink BWP for one ormore downlink receptions. The value of the one or more BWP indicatorfields may indicate an active uplink BWP for one or more uplinktransmissions.

A base station may semi-statically configure a UE with a defaultdownlink BWP within a set of configured downlink BWPs associated with aPCell. If the base station does not provide the default downlink BWP tothe UE, the default downlink BWP may be an initial active downlink BWP.The UE may determine which BWP is the initial active downlink BWP basedon a CORESET configuration obtained using the PBCH.

A base station may configure a UE with a BWP inactivity timer value fora PCell. The UE may start or restart a BWP inactivity timer at anyappropriate time. For example, the UE may start or restart the BWPinactivity timer (a) when the UE detects a DCI indicating an activedownlink BWP other than a default downlink BWP for a paired spectraoperation; or (b) when a UE detects a DCI indicating an active downlinkBWP or active uplink BWP other than a default downlink BWP or uplink BWPfor an unpaired spectra operation. If the UE does not detect DCI duringan interval of time (e.g., 1 ms or 0.5 ms), the UE may run the BWPinactivity timer toward expiration (for example, increment from zero tothe BWP inactivity timer value, or decrement from the BWP inactivitytimer value to zero). When the BWP inactivity timer expires, the UE mayswitch from the active downlink BWP to the default downlink BWP.

In an example, a base station may semi-statically configure a UE withone or more BWPs. A UE may switch an active BWP from a first BWP to asecond BWP in response to receiving a DCI indicating the second BWP asan active BWP and/or in response to an expiry of the BWP inactivitytimer (e.g., if the second BWP is the default BWP).

Downlink and uplink BWP switching (where BWP switching refers toswitching from a currently active BWP to a not currently active BWP) maybe performed independently in paired spectra. In unpaired spectra,downlink and uplink BWP switching may be performed simultaneously.Switching between configured BWPs may occur based on RRC signaling, DCI,expiration of a BWP inactivity timer, and/or an initiation of randomaccess.

FIG. 9 illustrates an example of bandwidth adaptation using threeconfigured BWPs for an NR carrier. A UE configured with the three BWPsmay switch from one BWP to another BWP at a switching point. In theexample illustrated in FIG. 9 , the BWPs include: a BWP 902 with abandwidth of 40 MHz and a subcarrier spacing of 15 kHz; a BWP 904 with abandwidth of 10 MHz and a subcarrier spacing of 15 kHz; and a BWP 906with a bandwidth of 20 MHz and a subcarrier spacing of 60 kHz. The BWP902 may be an initial active BWP, and the BWP 904 may be a default BWP.The UE may switch between BWPs at switching points. In the example ofFIG. 9 , the UE may switch from the BWP 902 to the BWP 904 at aswitching point 908. The switching at the switching point 908 may occurfor any suitable reason, for example, in response to an expiry of a BWPinactivity timer (indicating switching to the default BWP) and/or inresponse to receiving a DCI indicating BWP 904 as the active BWP. The UEmay switch at a switching point 910 from active BWP 904 to BWP 906 inresponse receiving a DCI indicating BWP 906 as the active BWP. The UEmay switch at a switching point 912 from active BWP 906 to BWP 904 inresponse to an expiry of a BWP inactivity timer and/or in responsereceiving a DCI indicating BWP 904 as the active BWP. The UE may switchat a switching point 914 from active BWP 904 to BWP 902 in responsereceiving a DCI indicating BWP 902 as the active BWP.

If a UE is configured for a secondary cell with a default downlink BWPin a set of configured downlink BWPs and a timer value, UE proceduresfor switching BWPs on a secondary cell may be the same/similar as thoseon a primary cell. For example, the UE may use the timer value and thedefault downlink BWP for the secondary cell in the same/similar manneras the UE would use these values for a primary cell.

To provide for greater data rates, two or more carriers can beaggregated and simultaneously transmitted to/from the same UE usingcarrier aggregation (CA). The aggregated carriers in CA may be referredto as component carriers (CCs). When CA is used, there are a number ofserving cells for the UE, one for a CC. The CCs may have threeconfigurations in the frequency domain.

FIG. 10A illustrates the three CA configurations with two CCs. In theintraband, contiguous configuration 1002, the two CCs are aggregated inthe same frequency band (frequency band A) and are located directlyadjacent to each other within the frequency band. In the intraband,non-contiguous configuration 1004, the two CCs are aggregated in thesame frequency band (frequency band A) and are separated in thefrequency band by a gap. In the interband configuration 1006, the twoCCs are located in frequency bands (frequency band A and frequency bandB).

In an example, up to 32 CCs may be aggregated. The aggregated CCs mayhave the same or different bandwidths, subcarrier spacing, and/orduplexing schemes (TDD or FDD). A serving cell for a UE using CA mayhave a downlink CC. For FDD, one or more uplink CCs may be optionallyconfigured for a serving cell. The ability to aggregate more downlinkcarriers than uplink carriers may be useful, for example, when the UEhas more data traffic in the downlink than in the uplink.

When CA is used, one of the aggregated cells for a UE may be referred toas a primary cell (PCell). The PCell may be the serving cell that the UEinitially connects to at RRC connection establishment, reestablishment,and/or handover. The PCell may provide the UE with NAS mobilityinformation and the security input. UEs may have different PCells. Inthe downlink, the carrier corresponding to the PCell may be referred toas the downlink primary CC (DL PCC). In the uplink, the carriercorresponding to the PCell may be referred to as the uplink primary CC(UL PCC). The other aggregated cells for the UE may be referred to assecondary cells (SCells). In an example, the SCells may be configuredafter the PCell is configured for the UE. For example, an SCell may beconfigured through an RRC Connection Reconfiguration procedure. In thedownlink, the carrier corresponding to an SCell may be referred to as adownlink secondary CC (DL SCC). In the uplink, the carrier correspondingto the SCell may be referred to as the uplink secondary CC (UL SCC).

Configured SCells for a UE may be activated and deactivated based on,for example, traffic and channel conditions. Deactivation of an SCellmay mean that PDCCH and PDSCH reception on the SCell is stopped andPUSCH, SRS, and CQI transmissions on the SCell are stopped. ConfiguredSCells may be activated and deactivated using a MAC CE with respect toFIG. 4B. For example, a MAC CE may use a bitmap (e.g., one bit perSCell) to indicate which SCells (e.g., in a subset of configured SCells)for the UE are activated or deactivated. Configured SCells may bedeactivated in response to an expiration of an SCell deactivation timer(e.g., one SCell deactivation timer per SCell).

Downlink control information, such as scheduling assignments andscheduling grants, for a cell may be transmitted on the cellcorresponding to the assignments and grants, which is known asself-scheduling. The DCI for the cell may be transmitted on anothercell, which is known as cross-carrier scheduling. Uplink controlinformation (e.g., HARQ acknowledgments and channel state feedback, suchas CQI, PMI, and/or RI) for aggregated cells may be transmitted on thePUCCH of the PCell. For a larger number of aggregated downlink CCs, thePUCCH of the PCell may become overloaded. Cells may be divided intomultiple PUCCH groups.

FIG. 10B illustrates an example of how aggregated cells may beconfigured into one or more PUCCH groups. A PUCCH group 1010 and a PUCCHgroup 1050 may include one or more downlink CCs, respectively. In theexample of FIG. 10B, the PUCCH group 1010 includes three downlink CCs: aPCell 1011, an SCell 1012, and an SCell 1013. The PUCCH group 1050includes three downlink CCs in the present example: a PCell 1051, anSCell 1052, and an SCell 1053. One or more uplink CCs may be configuredas a PCell 1021, an SCell 1022, and an SCell 1023. One or more otheruplink CCs may be configured as a primary Scell (PSCell) 1061, an SCell1062, and an SCell 1063. Uplink control information (UCI) related to thedownlink CCs of the PUCCH group 1010, shown as UCI 1031, UCI 1032, andUCI 1033, may be transmitted in the uplink of the PCell 1021. Uplinkcontrol information (UCI) related to the downlink CCs of the PUCCH group1050, shown as UCI 1071, UCI 1072, and UCI 1073, may be transmitted inthe uplink of the PSCell 1061. In an example, if the aggregated cellsdepicted in FIG. 10B were not divided into the PUCCH group 1010 and thePUCCH group 1050, a single uplink PCell to transmit UCI relating to thedownlink CCs, and the PCell may become overloaded. By dividingtransmissions of UCI between the PCell 1021 and the PSCell 1061,overloading may be prevented.

A cell, comprising a downlink carrier and optionally an uplink carrier,may be assigned with a physical cell ID and a cell index. The physicalcell ID or the cell index may identify a downlink carrier and/or anuplink carrier of the cell, for example, depending on the context inwhich the physical cell ID is used. A physical cell ID may be determinedusing a synchronization signal transmitted on a downlink componentcarrier. A cell index may be determined using RRC messages. In thedisclosure, a physical cell ID may be referred to as a carrier ID, and acell index may be referred to as a carrier index. For example, when thedisclosure refers to a first physical cell ID for a first downlinkcarrier, the disclosure may mean the first physical cell ID is for acell comprising the first downlink carrier. The same/similar concept mayapply to, for example, a carrier activation. When the disclosureindicates that a first carrier is activated, the specification may meanthat a cell comprising the first carrier is activated.

In CA, a multi-carrier nature of a PHY may be exposed to a MAC. In anexample, a HARQ entity may operate on a serving cell. A transport blockmay be generated per assignment/grant per serving cell. A transportblock and potential HARQ retransmissions of the transport block may bemapped to a serving cell.

In the downlink, a base station may transmit (e.g., unicast, multicast,and/or broadcast) one or more Reference Signals (RSs) to a UE (e.g.,PSS, SSS, CSI-RS, DMRS, and/or PT-RS, as shown in FIG. 5A). In theuplink, the UE may transmit one or more RSs to the base station (e.g.,DMRS, PT-RS, and/or SRS, as shown in FIG. 5B). The PSS and the SSS maybe transmitted by the base station and used by the UE to synchronize theUE to the base station. The PSS and the SSS may be provided in asynchronization signal (SS)/physical broadcast channel (PBCH) block thatincludes the PSS, the SSS, and the PBCH. The base station mayperiodically transmit a burst of SS/PBCH blocks.

FIG. 11A illustrates an example of an SS/PBCH block's structure andlocation. A burst of SS/PBCH blocks may include one or more SS/PBCHblocks (e.g., 4 SS/PBCH blocks, as shown in FIG. 11A). Bursts may betransmitted periodically (e.g., every 2 frames or 20 ms). A burst may berestricted to a half-frame (e.g., a first half-frame having a durationof 5 ms). It will be understood that FIG. 11A is an example, and thatthese parameters (number of SS/PBCH blocks per burst, periodicity ofbursts, position of burst within the frame) may be configured based on,for example: a carrier frequency of a cell in which the SS/PBCH block istransmitted; a numerology or subcarrier spacing of the cell; aconfiguration by the network (e.g., using RRC signaling); or any othersuitable factor. In an example, the UE may assume a subcarrier spacingfor the SS/PBCH block based on the carrier frequency being monitored,unless the radio network configured the UE to assume a differentsubcarrier spacing.

The SS/PBCH block may span one or more OFDM symbols in the time domain(e.g., 4 OFDM symbols, as shown in the example of FIG. 11A) and may spanone or more subcarriers in the frequency domain (e.g., 240 contiguoussubcarriers). The PSS, the SSS, and the PBCH may have a common centerfrequency. The PSS may be transmitted first and may span, for example, 1OFDM symbol and 127 subcarriers. The SSS may be transmitted after thePSS (e.g., two symbols later) and may span 1 OFDM symbol and 127subcarriers. The PBCH may be transmitted after the PSS (e.g., across thenext 3 OFDM symbols) and may span 240 subcarriers.

The location of the SS/PBCH block in the time and frequency domains maynot be known to the UE (e.g., if the UE is searching for the cell). Tofind and select the cell, the UE may monitor a carrier for the PSS. Forexample, the UE may monitor a frequency location within the carrier. Ifthe PSS is not found after a certain duration (e.g., 20 ms), the UE maysearch for the PSS at a different frequency location within the carrier,as indicated by a synchronization raster. If the PSS is found at alocation in the time and frequency domains, the UE may determine, basedon a known structure of the SS/PBCH block, the locations of the SSS andthe PBCH, respectively. The SS/PBCH block may be a cell-defining SSblock (CD-SSB). In an example, a primary cell may be associated with aCD-SSB. The CD-SSB may be located on a synchronization raster. In anexample, a cell selection/search and/or reselection may be based on theCD-SSB.

The SS/PBCH block may be used by the UE to determine one or moreparameters of the cell. For example, the UE may determine a physicalcell identifier (PCI) of the cell based on the sequences of the PSS andthe SSS, respectively. The UE may determine a location of a frameboundary of the cell based on the location of the SS/PBCH block. Forexample, the SS/PBCH block may indicate that it has been transmitted inaccordance with a transmission pattern, wherein a SS/PBCH block in thetransmission pattern is a known distance from the frame boundary.

The PBCH may use a QPSK modulation and may use forward error correction(FEC). The FEC may use polar coding. One or more symbols spanned by thePBCH may carry one or more DMRSs for demodulation of the PBCH. The PBCHmay include an indication of a current system frame number (SFN) of thecell and/or a SS/PBCH block timing index. These parameters mayfacilitate time synchronization of the UE to the base station. The PBCHmay include a master information block (MIB) used to provide the UE withone or more parameters. The MIB may be used by the UE to locateremaining minimum system information (RMSI) associated with the cell.The RMSI may include a System Information Block Type 1 (SIB1). The SIB1may contain information needed by the UE to access the cell. The UE mayuse one or more parameters of the MIB to monitor PDCCH, which may beused to schedule PDSCH. The PDSCH may include the SIB1. The SIB1 may bedecoded using parameters provided in the MIB. The PBCH may indicate anabsence of SIB1. Based on the PBCH indicating the absence of SIB1, theUE may be pointed to a frequency. The UE may search for an SS/PBCH blockat the frequency to which the UE is pointed.

The UE may assume that one or more SS/PBCH blocks transmitted with asame SS/PBCH block index are quasi co-located (QCLed) (e.g., having thesame/similar Doppler spread, Doppler shift, average gain, average delay,and/or spatial Rx parameters). The UE may not assume QCL for SS/PBCHblock transmissions having different SS/PBCH block indices.

SS/PBCH blocks (e.g., those within a half-frame) may be transmitted inspatial directions (e.g., using different beams that span a coveragearea of the cell). In an example, a first SS/PBCH block may betransmitted in a first spatial direction using a first beam, and asecond SS/PBCH block may be transmitted in a second spatial directionusing a second beam.

In an example, within a frequency span of a carrier, a base station maytransmit a plurality of SS/PBCH blocks. In an example, a first PCI of afirst SS/PBCH block of the plurality of SS/PBCH blocks may be differentfrom a second PCI of a second SS/PBCH block of the plurality of SS/PBCHblocks. The PCIs of SS/PBCH blocks transmitted in different frequencylocations may be different or the same.

The CSI-RS may be transmitted by the base station and used by the UE toacquire channel state information (CSI). The base station may configurethe UE with one or more CSI-RSs for channel estimation or any othersuitable purpose. The base station may configure a UE with one or moreof the same/similar CSI-RSs. The UE may measure the one or more CSI-RSs.The UE may estimate a downlink channel state and/or generate a CSIreport based on the measuring of the one or more downlink CSI-RSs. TheUE may provide the CSI report to the base station. The base station mayuse feedback provided by the UE (e.g., the estimated downlink channelstate) to perform link adaptation.

The base station may semi-statically configure the UE with one or moreCSI-RS resource sets. A CSI-RS resource may be associated with alocation in the time and frequency domains and a periodicity. The basestation may selectively activate and/or deactivate a CSI-RS resource.The base station may indicate to the UE that a CSI-RS resource in theCSI-RS resource set is activated and/or deactivated.

The base station may configure the UE to report CSI measurements. Thebase station may configure the UE to provide CSI reports periodically,aperiodically, or semi-persistently. For periodic CSI reporting, the UEmay be configured with a timing and/or periodicity of a plurality of CSIreports. For aperiodic CSI reporting, the base station may request a CSIreport. For example, the base station may command the UE to measure aconfigured CSI-RS resource and provide a CSI report relating to themeasurements. For semi-persistent CSI reporting, the base station mayconfigure the UE to transmit periodically, and selectively activate ordeactivate the periodic reporting. The base station may configure the UEwith a CSI-RS resource set and CSI reports using RRC signaling.

The CSI-RS configuration may comprise one or more parameters indicating,for example, up to 32 antenna ports. The UE may be configured to employthe same OFDM symbols for a downlink CSI-RS and a control resource set(CORESET) when the downlink CSI-RS and CORESET are spatially QCLed andresource elements associated with the downlink CSI-RS are outside of thephysical resource blocks (PRBs) configured for the CORESET. The UE maybe configured to employ the same OFDM symbols for downlink CSI-RS andSS/PBCH blocks when the downlink CSI-RS and SS/PBCH blocks are spatiallyQCLed and resource elements associated with the downlink CSI-RS areoutside of PRBs configured for the SS/PBCH blocks.

Downlink DMRSs may be transmitted by a base station and used by a UE forchannel estimation. For example, the downlink DMRS may be used forcoherent demodulation of one or more downlink physical channels (e.g.,PDSCH). An NR network may support one or more variable and/orconfigurable DMRS patterns for data demodulation. At least one downlinkDMRS configuration may support a front-loaded DMRS pattern. Afront-loaded DMRS may be mapped over one or more OFDM symbols (e.g., oneor two adjacent OFDM symbols). A base station may semi-staticallyconfigure the UE with a number (e.g. a maximum number) of front-loadedDMRS symbols for PDSCH. A DMRS configuration may support one or moreDMRS ports. For example, for single user-MIMO, a DMRS configuration maysupport up to eight orthogonal downlink DMRS ports per UE. Formultiuser-MIMO, a DMRS configuration may support up to 4 orthogonaldownlink DMRS ports per UE. A radio network may support (e.g., at leastfor CP-OFDM) a common DMRS structure for downlink and uplink, wherein aDMRS location, a DMRS pattern, and/or a scrambling sequence may be thesame or different. The base station may transmit a downlink DMRS and acorresponding PDSCH using the same precoding matrix. The UE may use theone or more downlink DMRSs for coherent demodulation/channel estimationof the PDSCH.

In an example, a transmitter (e.g., a base station) may use a precodermatrices for a part of a transmission bandwidth. For example, thetransmitter may use a first precoder matrix for a first bandwidth and asecond precoder matrix for a second bandwidth. The first precoder matrixand the second precoder matrix may be different based on the firstbandwidth being different from the second bandwidth. The UE may assumethat a same precoding matrix is used across a set of PRBs. The set ofPRBs may be denoted as a precoding resource block group (PRG).

A PDSCH may comprise one or more layers. The UE may assume that at leastone symbol with DMRS is present on a layer of the one or more layers ofthe PDSCH. A higher layer may configure up to 3 DMRSs for the PDSCH.

Downlink PT-RS may be transmitted by a base station and used by a UE forphase-noise compensation. Whether a downlink PT-RS is present or not maydepend on an RRC configuration. The presence and/or pattern of thedownlink PT-RS may be configured on a UE-specific basis using acombination of RRC signaling and/or an association with one or moreparameters employed for other purposes (e.g., modulation and codingscheme (MCS)), which may be indicated by DCI. When configured, a dynamicpresence of a downlink PT-RS may be associated with one or more DCIparameters comprising at least MCS. An NR network may support aplurality of PT-RS densities defined in the time and/or frequencydomains. When present, a frequency domain density may be associated withat least one configuration of a scheduled bandwidth. The UE may assume asame precoding for a DMRS port and a PT-RS port. A number of PT-RS portsmay be fewer than a number of DMRS ports in a scheduled resource.Downlink PT-RS may be confined in the scheduled time/frequency durationfor the UE. Downlink PT-RS may be transmitted on symbols to facilitatephase tracking at the receiver.

The UE may transmit an uplink DMRS to a base station for channelestimation. For example, the base station may use the uplink DMRS forcoherent demodulation of one or more uplink physical channels. Forexample, the UE may transmit an uplink DMRS with a PUSCH and/or a PUCCH.The uplink DM-RS may span a range of frequencies that is similar to arange of frequencies associated with the corresponding physical channel.The base station may configure the UE with one or more uplink DMRSconfigurations. At least one DMRS configuration may support afront-loaded DMRS pattern. The front-loaded DMRS may be mapped over oneor more OFDM symbols (e.g., one or two adjacent OFDM symbols). One ormore uplink DMRSs may be configured to transmit at one or more symbolsof a PUSCH and/or a PUCCH. The base station may semi-staticallyconfigure the UE with a number (e.g. maximum number) of front-loadedDMRS symbols for the PUSCH and/or the PUCCH, which the UE may use toschedule a single-symbol DMRS and/or a double-symbol DMRS. An NR networkmay support (e.g., for cyclic prefix orthogonal frequency divisionmultiplexing (CP-OFDM)) a common DMRS structure for downlink and uplink,wherein a DMRS location, a DMRS pattern, and/or a scrambling sequencefor the DMRS may be the same or different.

A PUSCH may comprise one or more layers, and the UE may transmit atleast one symbol with DMRS present on a layer of the one or more layersof the PUSCH. In an example, a higher layer may configure up to threeDMRSs for the PUSCH.

Uplink PT-RS (which may be used by a base station for phase trackingand/or phase-noise compensation) may or may not be present depending onan RRC configuration of the UE. The presence and/or pattern of uplinkPT-RS may be configured on a UE-specific basis by a combination of RRCsignaling and/or one or more parameters employed for other purposes(e.g., Modulation and Coding Scheme (MCS)), which may be indicated byDCI. When configured, a dynamic presence of uplink PT-RS may beassociated with one or more DCI parameters comprising at least MCS. Aradio network may support a plurality of uplink PT-RS densities definedin time/frequency domain. When present, a frequency domain density maybe associated with at least one configuration of a scheduled bandwidth.The UE may assume a same precoding for a DMRS port and a PT-RS port. Anumber of PT-RS ports may be fewer than a number of DMRS ports in ascheduled resource. For example, uplink PT-RS may be confined in thescheduled time/frequency duration for the UE.

SRS may be transmitted by a UE to a base station for channel stateestimation to support uplink channel dependent scheduling and/or linkadaptation. SRS transmitted by the UE may allow a base station toestimate an uplink channel state at one or more frequencies. A schedulerat the base station may employ the estimated uplink channel state toassign one or more resource blocks for an uplink PUSCH transmission fromthe UE. The base station may semi-statically configure the UE with oneor more SRS resource sets. For an SRS resource set, the base station mayconfigure the UE with one or more SRS resources. An SRS resource setapplicability may be configured by a higher layer (e.g., RRC) parameter.For example, when a higher layer parameter indicates beam management, anSRS resource in a SRS resource set of the one or more SRS resource sets(e.g., with the same/similar time domain behavior, periodic, aperiodic,and/or the like) may be transmitted at a time instant (e.g.,simultaneously). The UE may transmit one or more SRS resources in SRSresource sets. An NR network may support aperiodic, periodic and/orsemi-persistent SRS transmissions. The UE may transmit SRS resourcesbased on one or more trigger types, wherein the one or more triggertypes may comprise higher layer signaling (e.g., RRC) and/or one or moreDCI formats. In an example, at least one DCI format may be employed forthe UE to select at least one of one or more configured SRS resourcesets. An SRS trigger type 0 may refer to an SRS triggered based on ahigher layer signaling. An SRS trigger type 1 may refer to an SRStriggered based on one or more DCI formats. In an example, when PUSCHand SRS are transmitted in a same slot, the UE may be configured totransmit SRS after a transmission of a PUSCH and a corresponding uplinkDMRS.

The base station may semi-statically configure the UE with one or moreSRS configuration parameters indicating at least one of following: a SRSresource configuration identifier; a number of SRS ports; time domainbehavior of an SRS resource configuration (e.g., an indication ofperiodic, semi-persistent, or aperiodic SRS); slot, mini-slot, and/orsubframe level periodicity; offset for a periodic and/or an aperiodicSRS resource; a number of OFDM symbols in an SRS resource; a startingOFDM symbol of an SRS resource; an SRS bandwidth; a frequency hoppingbandwidth; a cyclic shift; and/or an SRS sequence ID.

An antenna port is defined such that the channel over which a symbol onthe antenna port is conveyed can be inferred from the channel over whichanother symbol on the same antenna port is conveyed. If a first symboland a second symbol are transmitted on the same antenna port, thereceiver may infer the channel (e.g., fading gain, multipath delay,and/or the like) for conveying the second symbol on the antenna port,from the channel for conveying the first symbol on the antenna port. Afirst antenna port and a second antenna port may be referred to as quasico-located (QCLed) if one or more large-scale properties of the channelover which a first symbol on the first antenna port is conveyed may beinferred from the channel over which a second symbol on a second antennaport is conveyed. The one or more large-scale properties may comprise atleast one of: a delay spread; a Doppler spread; a Doppler shift; anaverage gain; an average delay; and/or spatial Receiving (Rx)parameters.

Channels that use beamforming require beam management. Beam managementmay comprise beam measurement, beam selection, and beam indication. Abeam may be associated with one or more reference signals. For example,a beam may be identified by one or more beamformed reference signals.The UE may perform downlink beam measurement based on downlink referencesignals (e.g., a channel state information reference signal (CSI-RS))and generate a beam measurement report. The UE may perform the downlinkbeam measurement procedure after an RRC connection is set up with a basestation.

FIG. 11B illustrates an example of channel state information referencesignals (CSI-RSs) that are mapped in the time and frequency domains. Asquare shown in FIG. 11B may span a resource block (RB) within abandwidth of a cell. A base station may transmit one or more RRCmessages comprising CSI-RS resource configuration parameters indicatingone or more CSI-RSs. One or more of the following parameters may beconfigured by higher layer signaling (e.g., RRC and/or MAC signaling)for a CSI-RS resource configuration: a CSI-RS resource configurationidentity, a number of CSI-RS ports, a CSI-RS configuration (e.g., symboland resource element (RE) locations in a subframe), a CSI-RS subframeconfiguration (e.g., subframe location, offset, and periodicity in aradio frame), a CSI-RS power parameter, a CSI-RS sequence parameter, acode division multiplexing (CDM) type parameter, a frequency density, atransmission comb, quasi co-location (QCL) parameters (e.g.,QCL-scramblingidentity, crs-portscount, mbsfn-subframeconfiglist,csi-rs-configZPid, qcl-csi-rs-configNZPid), and/or other radio resourceparameters.

The three beams illustrated in FIG. 11B may be configured for a UE in aUE-specific configuration. Three beams are illustrated in FIG. 11B (beam#1, beam #2, and beam #3), more or fewer beams may be configured. Beam#1 may be allocated with CSI-RS 1101 that may be transmitted in one ormore subcarriers in an RB of a first symbol. Beam #2 may be allocatedwith CSI-RS 1102 that may be transmitted in one or more subcarriers inan RB of a second symbol. Beam #3 may be allocated with CSI-RS 1103 thatmay be transmitted in one or more subcarriers in an RB of a thirdsymbol. By using frequency division multiplexing (FDM), a base stationmay use other subcarriers in a same RB (for example, those that are notused to transmit CSI-RS 1101) to transmit another CSI-RS associated witha beam for another UE. By using time domain multiplexing (TDM), beamsused for the UE may be configured such that beams for the UE use symbolsfrom beams of other UEs.

CSI-RSs such as those illustrated in FIG. 11B (e.g., CSI-RS 1101, 1102,1103) may be transmitted by the base station and used by the UE for oneor more measurements. For example, the UE may measure a reference signalreceived power (RSRP) of configured CSI-RS resources. The base stationmay configure the UE with a reporting configuration and the UE mayreport the RSRP measurements to a network (for example, via one or morebase stations) based on the reporting configuration. In an example, thebase station may determine, based on the reported measurement results,one or more transmission configuration indication (TCI) statescomprising a number of reference signals. In an example, the basestation may indicate one or more TCI states to the UE (e.g., via RRCsignaling, a MAC CE, and/or a DCI). The UE may receive a downlinktransmission with a receive (Rx) beam determined based on the one ormore TCI states. In an example, the UE may or may not have a capabilityof beam correspondence. If the UE has the capability of beamcorrespondence, the UE may determine a spatial domain filter of atransmit (Tx) beam based on a spatial domain filter of the correspondingRx beam. If the UE does not have the capability of beam correspondence,the UE may perform an uplink beam selection procedure to determine thespatial domain filter of the Tx beam. The UE may perform the uplink beamselection procedure based on one or more sounding reference signal (SRS)resources configured to the UE by the base station. The base station mayselect and indicate uplink beams for the UE based on measurements of theone or more SRS resources transmitted by the UE.

In a beam management procedure, a UE may assess (e.g., measure) achannel quality of one or more beam pair links, a beam pair linkcomprising a transmitting beam transmitted by a base station and areceiving beam received by the UE. Based on the assessment, the UE maytransmit a beam measurement report indicating one or more beam pairquality parameters comprising, e.g., one or more beam identifications(e.g., a beam index, a reference signal index, or the like), RSRP, aprecoding matrix indicator (PMI), a channel quality indicator (CQI),and/or a rank indicator (RI).

FIG. 12A illustrates examples of three downlink beam managementprocedures: P1, P2, and P3. Procedure P1 may enable a UE measurement ontransmit (Tx) beams of a transmission reception point (TRP) (or multipleTRPs), e.g., to support a selection of one or more base station Tx beamsand/or UE Rx beams (shown as ovals in the top row and bottom row,respectively, of P1). Beamforming at a TRP may comprise a Tx beam sweepfor a set of beams (shown, in the top rows of P1 and P2, as ovalsrotated in a counter-clockwise direction indicated by the dashed arrow).Beamforming at a UE may comprise an Rx beam sweep for a set of beams(shown, in the bottom rows of P1 and P3, as ovals rotated in a clockwisedirection indicated by the dashed arrow). Procedure P2 may be used toenable a UE measurement on Tx beams of a TRP (shown, in the top row ofP2, as ovals rotated in a counter-clockwise direction indicated by thedashed arrow). The UE and/or the base station may perform procedure P2using a smaller set of beams than is used in procedure P1, or usingnarrower beams than the beams used in procedure P1. This may be referredto as beam refinement. The UE may perform procedure P3 for Rx beamdetermination by using the same Tx beam at the base station and sweepingan Rx beam at the UE.

FIG. 12B illustrates examples of three uplink beam managementprocedures: U1, U2, and U3. Procedure U1 may be used to enable a basestation to perform a measurement on Tx beams of a UE, e.g., to support aselection of one or more UE Tx beams and/or base station Rx beams (shownas ovals in the top row and bottom row, respectively, of U1).Beamforming at the UE may include, e.g., a Tx beam sweep from a set ofbeams (shown in the bottom rows of U1 and U3 as ovals rotated in aclockwise direction indicated by the dashed arrow). Beamforming at thebase station may include, e.g., an Rx beam sweep from a set of beams(shown, in the top rows of U1 and U2, as ovals rotated in acounter-clockwise direction indicated by the dashed arrow). Procedure U2may be used to enable the base station to adjust its Rx beam when the UEuses a fixed Tx beam. The UE and/or the base station may performprocedure U2 using a smaller set of beams than is used in procedure P1,or using narrower beams than the beams used in procedure P1. This may bereferred to as beam refinement The UE may perform procedure U3 to adjustits Tx beam when the base station uses a fixed Rx beam.

A UE may initiate a beam failure recovery (BFR) procedure based ondetecting a beam failure. The UE may transmit a BFR request (e.g., apreamble, a UCI, an SR, a MAC CE, and/or the like) based on theinitiating of the BFR procedure. The UE may detect the beam failurebased on a determination that a quality of beam pair link(s) of anassociated control channel is unsatisfactory (e.g., having an error ratehigher than an error rate threshold, a received signal power lower thana received signal power threshold, an expiration of a timer, and/or thelike).

The UE may measure a quality of a beam pair link using one or morereference signals (RSs) comprising one or more SS/PBCH blocks, one ormore CSI-RS resources, and/or one or more demodulation reference signals(DMRSs). A quality of the beam pair link may be based on one or more ofa block error rate (BLER), an RSRP value, a signal to interference plusnoise ratio (SINR) value, a reference signal received quality (RSRQ)value, and/or a CSI value measured on RS resources. The base station mayindicate that an RS resource is quasi co-located (QCLed) with one ormore DM-RSs of a channel (e.g., a control channel, a shared datachannel, and/or the like). The RS resource and the one or more DMRSs ofthe channel may be QCLed when the channel characteristics (e.g., Dopplershift, Doppler spread, average delay, delay spread, spatial Rxparameter, fading, and/or the like) from a transmission via the RSresource to the UE are similar or the same as the channelcharacteristics from a transmission via the channel to the UE.

A network (e.g., a gNB and/or an ng-eNB of a network) and/or the UE mayinitiate a random access procedure. A UE in an RRC_IDLE state and/or anRRC_INACTIVE state may initiate the random access procedure to request aconnection setup to a network. The UE may initiate the random accessprocedure from an RRC_CONNECTED state. The UE may initiate the randomaccess procedure to request uplink resources (e.g., for uplinktransmission of an SR when there is no PUCCH resource available) and/oracquire uplink timing (e.g., when uplink synchronization status isnon-synchronized). The UE may initiate the random access procedure torequest one or more system information blocks (SIBs) (e.g., other systeminformation such as SIB2, SIB3, and/or the like). The UE may initiatethe random access procedure for a beam failure recovery request. Anetwork may initiate a random access procedure for a handover and/or forestablishing time alignment for an SCell addition.

FIG. 13A illustrates a four-step contention-based random accessprocedure. Prior to initiation of the procedure, a base station maytransmit a configuration message 1310 to the UE. The procedureillustrated in FIG. 13A comprises transmission of four messages: a Msg 11311, a Msg 2 1312, a Msg 3 1313, and a Msg 4 1314. The Msg 1 1311 mayinclude and/or be referred to as a preamble (or a random accesspreamble). The Msg 2 1312 may include and/or be referred to as a randomaccess response (RAR).

The configuration message 1310 may be transmitted, for example, usingone or more RRC messages. The one or more RRC messages may indicate oneor more random access channel (RACH) parameters to the UE. The one ormore RACH parameters may comprise at least one of following: generalparameters for one or more random access procedures (e.g.,RACH-configGeneral); cell-specific parameters (e.g., RACH-ConfigCommon);and/or dedicated parameters (e.g., RACH-configDedicated). The basestation may broadcast or multicast the one or more RRC messages to oneor more UEs. The one or more RRC messages may be UE-specific (e.g.,dedicated RRC messages transmitted to a UE in an RRC_CONNECTED stateand/or in an RRC_INACTIVE state). The UE may determine, based on the oneor more RACH parameters, a time-frequency resource and/or an uplinktransmit power for transmission of the Msg 1 1311 and/or the Msg 3 1313.Based on the one or more RACH parameters, the UE may determine areception timing and a downlink channel for receiving the Msg 2 1312 andthe Msg 4 1314.

The one or more RACH parameters provided in the configuration message1310 may indicate one or more Physical RACH (PRACH) occasions availablefor transmission of the Msg 1 1311. The one or more PRACH occasions maybe predefined. The one or more RACH parameters may indicate one or moreavailable sets of one or more PRACH occasions (e.g., prach-ConfigIndex).The one or more RACH parameters may indicate an association between (a)one or more PRACH occasions and (b) one or more reference signals. Theone or more RACH parameters may indicate an association between (a) oneor more preambles and (b) one or more reference signals. The one or morereference signals may be SS/PBCH blocks and/or CSI-RSs. For example, theone or more RACH parameters may indicate a number of SS/PBCH blocksmapped to a PRACH occasion and/or a number of preambles mapped to aSS/PBCH blocks.

The one or more RACH parameters provided in the configuration message1310 may be used to determine an uplink transmit power of Msg 1 1311and/or Msg 3 1313. For example, the one or more RACH parameters mayindicate a reference power for a preamble transmission (e.g., a receivedtarget power and/or an initial power of the preamble transmission).There may be one or more power offsets indicated by the one or more RACHparameters. For example, the one or more RACH parameters may indicate: apower ramping step; a power offset between SSB and CSI-RS; a poweroffset between transmissions of the Msg 1 1311 and the Msg 3 1313;and/or a power offset value between preamble groups. The one or moreRACH parameters may indicate one or more thresholds based on which theUE may determine at least one reference signal (e.g., an SSB and/orCSI-RS) and/or an uplink carrier (e.g., a normal uplink (NUL) carrierand/or a supplemental uplink (SUL) carrier).

The Msg 1 1311 may include one or more preamble transmissions (e.g., apreamble transmission and one or more preamble retransmissions). An RRCmessage may be used to configure one or more preamble groups (e.g.,group A and/or group B). A preamble group may comprise one or morepreambles. The UE may determine the preamble group based on a pathlossmeasurement and/or a size of the Msg 3 1313. The UE may measure an RSRPof one or more reference signals (e.g., SSBs and/or CSI-RSs) anddetermine at least one reference signal having an RSRP above an RSRPthreshold (e.g., rsrp-ThresholdSSB and/or rsrp-ThresholdCSI-RS). The UEmay select at least one preamble associated with the one or morereference signals and/or a selected preamble group, for example, if theassociation between the one or more preambles and the at least onereference signal is configured by an RRC message.

The UE may determine the preamble based on the one or more RACHparameters provided in the configuration message 1310. For example, theUE may determine the preamble based on a pathloss measurement, an RSRPmeasurement, and/or a size of the Msg 3 1313. As another example, theone or more RACH parameters may indicate: a preamble format; a maximumnumber of preamble transmissions; and/or one or more thresholds fordetermining one or more preamble groups (e.g., group A and group B). Abase station may use the one or more RACH parameters to configure the UEwith an association between one or more preambles and one or morereference signals (e.g., SSBs and/or CSI-RSs). If the association isconfigured, the UE may determine the preamble to include in Msg 1 1311based on the association. The Msg 1 1311 may be transmitted to the basestation via one or more PRACH occasions. The UE may use one or morereference signals (e.g., SSBs and/or CSI-RSs) for selection of thepreamble and for determining of the PRACH occasion. One or more RACHparameters (e.g., ra-ssb-OccasionMskIndex and/or ra-OccasionList) mayindicate an association between the PRACH occasions and the one or morereference signals.

The UE may perform a preamble retransmission if no response is receivedfollowing a preamble transmission. The UE may increase an uplinktransmit power for the preamble retransmission. The UE may select aninitial preamble transmit power based on a pathloss measurement and/or atarget received preamble power configured by the network. The UE maydetermine to retransmit a preamble and may ramp up the uplink transmitpower. The UE may receive one or more RACH parameters (e.g.,PREAMBLE_POWER_RAMPING_STEP) indicating a ramping step for the preambleretransmission. The ramping step may be an amount of incrementalincrease in uplink transmit power for a retransmission. The UE may rampup the uplink transmit power if the UE determines a reference signal(e.g., SSB and/or CSI-RS) that is the same as a previous preambletransmission. The UE may count a number of preamble transmissions and/orretransmissions (e.g., PREAMBLE_TRANSMISSION_COUNTER). The UE maydetermine that a random access procedure completed unsuccessfully, forexample, if the number of preamble transmissions exceeds a thresholdconfigured by the one or more RACH parameters (e.g., preambleTransMax).

The Msg 2 1312 received by the UE may include an RAR. In some scenarios,the Msg 2 1312 may include multiple RARs corresponding to multiple UEs.The Msg 2 1312 may be received after or in response to the transmittingof the Msg 1 1311. The Msg 2 1312 may be scheduled on the DL-SCH andindicated on a PDCCH using a random access RNTI (RA-RNTI). The Msg 21312 may indicate that the Msg 1 1311 was received by the base station.The Msg 2 1312 may include a time-alignment command that may be used bythe UE to adjust the UE's transmission timing, a scheduling grant fortransmission of the Msg 3 1313, and/or a Temporary Cell RNTI (TC-RNTI).After transmitting a preamble, the UE may start a time window (e.g.,ra-ResponseWindow) to monitor a PDCCH for the Msg 2 1312. The UE maydetermine when to start the time window based on a PRACH occasion thatthe UE uses to transmit the preamble. For example, the UE may start thetime window one or more symbols after a last symbol of the preamble(e.g., at a first PDCCH occasion from an end of a preambletransmission). The one or more symbols may be determined based on anumerology. The PDCCH may be in a common search space (e.g., aType1-PDCCH common search space) configured by an RRC message. The UEmay identify the RAR based on a Radio Network Temporary Identifier(RNTI). RNTIs may be used depending on one or more events initiating therandom access procedure. The UE may use random access RNTI (RA-RNTI).The RA-RNTI may be associated with PRACH occasions in which the UEtransmits a preamble. For example, the UE may determine the RA-RNTIbased on: an OFDM symbol index; a slot index; a frequency domain index;and/or a UL carrier indicator of the PRACH occasions. An example ofRA-RNTI may be as follows:

RA-RNTI=1+s_id+14×t_id+14×80×f_id+14×80×8×ul_carrier_id

-   -   where s_id may be an index of a first OFDM symbol of the PRACH        occasion (e.g., 0≤s_id<14), t_id may be an index of a first slot        of the PRACH occasion in a system frame (e.g., 0≤t_id<80), f_id        may be an index of the PRACH occasion in the frequency domain        (e.g., 0≤f_id<8), and ul_carrier_id may be a UL carrier used for        a preamble transmission (e.g., 0 for an NUL carrier, and 1 for        an SUL carrier).    -   The UE may transmit the Msg 3 1313 in response to a successful        reception of the Msg 2 1312 (e.g., using resources identified in        the Msg 2 1312). The Msg 3 1313 may be used for contention        resolution in, for example, the contention-based random access        procedure illustrated in FIG. 13A. In some scenarios, a        plurality of UEs may transmit a same preamble to a base station        and the base station may provide an RAR that corresponds to a        UE. Collisions may occur if the plurality of UEs interpret the        RAR as corresponding to themselves. Contention resolution (e.g.,        using the Msg 3 1313 and the Msg 4 1314) may be used to increase        the likelihood that the UE does not incorrectly use an identity        of another the UE. To perform contention resolution, the UE may        include a device identifier in the Msg 3 1313 (e.g., a C-RNTI if        assigned, a TC RNTI included in the Msg 2 1312, and/or any other        suitable identifier).

The Msg 4 1314 may be received after or in response to the transmittingof the Msg 3 1313. If a C-RNTI was included in the Msg 3 1313, the basestation will address the UE on the PDCCH using the C-RNTI. If the UE'sunique C-RNTI is detected on the PDCCH, the random access procedure isdetermined to be successfully completed. If a TC-RNTI is included in theMsg 3 1313 (e.g., if the UE is in an RRC_IDLE state or not otherwiseconnected to the base station), Msg 4 1314 will be received using aDL-SCH associated with the TC-RNTI. If a MAC PDU is successfully decodedand a MAC PDU comprises the UE contention resolution identity MAC CEthat matches or otherwise corresponds with the CCCH SDU sent (e.g.,transmitted) in Msg 3 1313, the UE may determine that the contentionresolution is successful and/or the UE may determine that the randomaccess procedure is successfully completed.

The UE may be configured with a supplementary uplink (SUL) carrier and anormal uplink (NUL) carrier. An initial access (e.g., random accessprocedure) may be supported in an uplink carrier. For example, a basestation may configure the UE with two separate RACH configurations: onefor an SUL carrier and the other for an NUL carrier. For random accessin a cell configured with an SUL carrier, the network may indicate whichcarrier to use (NUL or SUL). The UE may determine the SUL carrier, forexample, if a measured quality of one or more reference signals is lowerthan a broadcast threshold. Uplink transmissions of the random accessprocedure (e.g., the Msg 1 1311 and/or the Msg 3 1313) may remain on theselected carrier. The UE may switch an uplink carrier during the randomaccess procedure (e.g., between the Msg 1 1311 and the Msg 3 1313) inone or more cases. For example, the UE may determine and/or switch anuplink carrier for the Msg 1 1311 and/or the Msg 3 1313 based on achannel clear assessment (e.g., a listen-before-talk).

FIG. 13B illustrates a two-step contention-free random access procedure.Similar to the four-step contention-based random access procedureillustrated in FIG. 13A, a base station may, prior to initiation of theprocedure, transmit a configuration message 1320 to the UE. Theconfiguration message 1320 may be analogous in some respects to theconfiguration message 1310. The procedure illustrated in FIG. 13Bcomprises transmission of two messages: a Msg 1 1321 and a Msg 2 1322.The Msg 1 1321 and the Msg 2 1322 may be analogous in some respects tothe Msg 1 1311 and a Msg 2 1312 illustrated in FIG. 13A, respectively.As will be understood from FIGS. 13A and 13B, the contention-free randomaccess procedure may not include messages analogous to the Msg 3 1313and/or the Msg 4 1314.

The contention-free random access procedure illustrated in FIG. 13B maybe initiated for a beam failure recovery, other SI request, SCelladdition, and/or handover. For example, a base station may indicate orassign to the UE the preamble to be used for the Msg 1 1321. The UE mayreceive, from the base station via PDCCH and/or RRC, an indication of apreamble (e.g., ra-PreambleIndex).

After transmitting a preamble, the UE may start a time window (e.g.,ra-ResponseWindow) to monitor a PDCCH for the RAR. In the event of abeam failure recovery request, the base station may configure the UEwith a separate time window and/or a separate PDCCH in a search spaceindicated by an RRC message (e.g., recoverySearchSpaceId). The UE maymonitor for a PDCCH transmission addressed to a Cell RNTI (C-RNTI) onthe search space. In the contention-free random access procedureillustrated in FIG. 13B, the UE may determine that a random accessprocedure successfully completes after or in response to transmission ofMsg 1 1321 and reception of a corresponding Msg 2 1322. The UE maydetermine that a random access procedure successfully completes, forexample, if a PDCCH transmission is addressed to a C-RNTI. The UE maydetermine that a random access procedure successfully completes, forexample, if the UE receives an RAR comprising a preamble identifiercorresponding to a preamble transmitted by the UE and/or the RARcomprises a MAC sub-PDU with the preamble identifier. The UE maydetermine the response as an indication of an acknowledgement for an SIrequest.

FIG. 13C illustrates another two-step random access procedure. Similarto the random access procedures illustrated in FIGS. 13A and 13B, a basestation may, prior to initiation of the procedure, transmit aconfiguration message 1330 to the UE. The configuration message 1330 maybe analogous in some respects to the configuration message 1310 and/orthe configuration message 1320. The procedure illustrated in FIG. 13Ccomprises transmission of two messages: a Msg A 1331 and a Msg B 1332.

Msg A 1331 may be transmitted in an uplink transmission by the UE. Msg A1331 may comprise one or more transmissions of a preamble 1341 and/orone or more transmissions of a transport block 1342. The transport block1342 may comprise contents that are similar and/or equivalent to thecontents of the Msg 3 1313 illustrated in FIG. 13A. The transport block1342 may comprise UCI (e.g., an SR, a HARQ ACK/NACK, and/or the like).The UE may receive the Msg B 1332 after or in response to transmittingthe Msg A 1331. The Msg B 1332 may comprise contents that are similarand/or equivalent to the contents of the Msg 2 1312 (e.g., an RAR)illustrated in FIGS. 13A and 13B and/or the Msg 4 1314 illustrated inFIG. 13A.

The UE may initiate the two-step random access procedure in FIG. 13C forlicensed spectrum and/or unlicensed spectrum. The UE may determine,based on one or more factors, whether to initiate the two-step randomaccess procedure. The one or more factors may be: a radio accesstechnology in use (e.g., LTE, NR, and/or the like); whether the UE hasvalid TA or not; a cell size; the UE's RRC state; a type of spectrum(e.g., licensed vs. unlicensed); and/or any other suitable factors.

The UE may determine, based on two-step RACH parameters included in theconfiguration message 1330, a radio resource and/or an uplink transmitpower for the preamble 1341 and/or the transport block 1342 included inthe Msg A 1331. The RACH parameters may indicate a modulation and codingschemes (MCS), a time-frequency resource, and/or a power control for thepreamble 1341 and/or the transport block 1342. A time-frequency resourcefor transmission of the preamble 1341 (e.g., a PRACH) and atime-frequency resource for transmission of the transport block 1342(e.g., a PUSCH) may be multiplexed using FDM, TDM, and/or CDM. The RACHparameters may enable the UE to determine a reception timing and adownlink channel for monitoring for and/or receiving Msg B 1332.

The transport block 1342 may comprise data (e.g., delay-sensitive data),an identifier of the UE, security information, and/or device information(e.g., an International Mobile Subscriber Identity (IMSI)). The basestation may transmit the Msg B 1332 as a response to the Msg A 1331. TheMsg B 1332 may comprise at least one of following: a preambleidentifier; a timing advance command; a power control command; an uplinkgrant (e.g., a radio resource assignment and/or an MCS); a UE identifierfor contention resolution; and/or an RNTI (e.g., a C-RNTI or a TC-RNTI).The UE may determine that the two-step random access procedure issuccessfully completed if: a preamble identifier in the Msg B 1332 ismatched to a preamble transmitted by the UE; and/or the identifier ofthe UE in Msg B 1332 is matched to the identifier of the UE in the Msg A1331 (e.g., the transport block 1342).

A UE and a base station may exchange control signaling. The controlsignaling may be referred to as L1/L2 control signaling and mayoriginate from the PHY layer (e.g., layer 1) and/or the MAC layer (e.g.,layer 2). The control signaling may comprise downlink control signalingtransmitted from the base station to the UE and/or uplink controlsignaling transmitted from the UE to the base station.

The downlink control signaling may comprise: a downlink schedulingassignment; an uplink scheduling grant indicating uplink radio resourcesand/or a transport format; a slot format information; a preemptionindication; a power control command; and/or any other suitablesignaling. The UE may receive the downlink control signaling in apayload transmitted by the base station on a physical downlink controlchannel (PDCCH). The payload transmitted on the PDCCH may be referred toas downlink control information (DCI). In some scenarios, the PDCCH maybe a group common PDCCH (GC-PDCCH) that is common to a group of UEs.

A base station may attach one or more cyclic redundancy check (CRC)parity bits to a DCI in order to facilitate detection of transmissionerrors. When the DCI is intended for a UE (or a group of the UEs), thebase station may scramble the CRC parity bits with an identifier of theUE (or an identifier of the group of the UEs). Scrambling the CRC paritybits with the identifier may comprise Modulo-2 addition (or an exclusiveOR operation) of the identifier value and the CRC parity bits. Theidentifier may comprise a 16-bit value of a radio network temporaryidentifier (RNTI).

DCIs may be used for different purposes. A purpose may be indicated bythe type of RNTI used to scramble the CRC parity bits. For example, aDCI having CRC parity bits scrambled with a paging RNTI (P-RNTI) mayindicate paging information and/or a system information changenotification. The P-RNTI may be predefined as “FFFE” in hexadecimal. ADCI having CRC parity bits scrambled with a system information RNTI(SI-RNTI) may indicate a broadcast transmission of the systeminformation. The SI-RNTI may be predefined as “FFFF” in hexadecimal. ADCI having CRC parity bits scrambled with a random access RNTI (RA-RNTI)may indicate a random access response (RAR). A DCI having CRC paritybits scrambled with a cell RNTI (C-RNTI) may indicate a dynamicallyscheduled unicast transmission and/or a triggering of PDCCH-orderedrandom access. A DCI having CRC parity bits scrambled with a temporarycell RNTI (TC-RNTI) may indicate a contention resolution (e.g., a Msg 3analogous to the Msg 3 1313 illustrated in FIG. 13A). Other RNTIsconfigured to the UE by a base station may comprise a ConfiguredScheduling RNTI (CS-RNTI), a Transmit Power Control-PUCCH RNTI(TPC-PUCCH-RNTI), a Transmit Power Control-PUSCH RNTI (TPC-PUSCH-RNTI),a Transmit Power Control-SRS RNTI (TPC-SRS-RNTI), an Interruption RNTI(INT-RNTI), a Slot Format Indication RNTI (SFI-RNTI), a Semi-PersistentCSI RNTI (SP-CSI-RNTI), a Modulation and Coding Scheme Cell RNTI(MCS-C-RNTI), and/or the like.

Depending on the purpose and/or content of a DCI, the base station maytransmit the DCIs with one or more DCI formats. For example, DCI format0_0 may be used for scheduling of PUSCH in a cell. DCI format 0_0 may bea fallback DCI format (e.g., with compact DCI payloads). DCI format 0_1may be used for scheduling of PUSCH in a cell (e.g., with more DCIpayloads than DCI format 0_0). DCI format 1_0 may be used for schedulingof PDSCH in a cell. DCI format 1_0 may be a fallback DCI format (e.g.,with compact DCI payloads). DCI format 1_1 may be used for scheduling ofPDSCH in a cell (e.g., with more DCI payloads than DCI format 1_0). DCIformat 2_0 may be used for providing a slot format indication to a groupof UEs. DCI format 2_1 may be used for notifying a group of UEs of aphysical resource block and/or OFDM symbol where the UE may assume notransmission is intended to the UE. DCI format 2_2 may be used fortransmission of a transmit power control (TPC) command for PUCCH orPUSCH. DCI format 2_3 may be used for transmission of a group of TPCcommands for SRS transmissions by one or more UEs. DCI format(s) for newfunctions may be defined in future releases. DCI formats may havedifferent DCI sizes, or may share the same DCI size.

After scrambling a DCI with a RNTI, the base station may process the DCIwith channel coding (e.g., polar coding), rate matching, scramblingand/or QPSK modulation. A base station may map the coded and modulatedDCI on resource elements used and/or configured for a PDCCH. Based on apayload size of the DCI and/or a coverage of the base station, the basestation may transmit the DCI via a PDCCH occupying a number ofcontiguous control channel elements (CCEs). The number of the contiguousCCEs (referred to as aggregation level) may be 1, 2, 4, 8, 16, and/orany other suitable number. A CCE may comprise a number (e.g., 6) ofresource-element groups (REGs). A REG may comprise a resource block inan OFDM symbol. The mapping of the coded and modulated DCI on theresource elements may be based on mapping of CCEs and REGs (e.g.,CCE-to-REG mapping).

FIG. 14A illustrates an example of CORESET configurations for abandwidth part. The base station may transmit a DCI via a PDCCH on oneor more control resource sets (CORESETs). A CORESET may comprise atime-frequency resource in which the UE tries to decode a DCI using oneor more search spaces. The base station may configure a CORESET in thetime-frequency domain. In the example of FIG. 14A, a first CORESET 1401and a second CORESET 1402 occur at the first symbol in a slot. The firstCORESET 1401 overlaps with the second CORESET 1402 in the frequencydomain. A third CORESET 1403 occurs at a third symbol in the slot. Afourth CORESET 1404 occurs at the seventh symbol in the slot. CORESETsmay have a different number of resource blocks in frequency domain.

FIG. 14B illustrates an example of a CCE-to-REG mapping for DCItransmission on a CORESET and PDCCH processing. The CCE-to-REG mappingmay be an interleaved mapping (e.g., for the purpose of providingfrequency diversity) or a non-interleaved mapping (e.g., for thepurposes of facilitating interference coordination and/orfrequency-selective transmission of control channels). The base stationmay perform different or same CCE-to-REG mapping on different CORESETs.A CORESET may be associated with a CCE-to-REG mapping by RRCconfiguration. A CORESET may be configured with an antenna port quasico-location (QCL) parameter. The antenna port QCL parameter may indicateQCL information of a demodulation reference signal (DMRS) for PDCCHreception in the CORESET.

The base station may transmit, to the UE, RRC messages comprisingconfiguration parameters of one or more CORESETs and one or more searchspace sets. The configuration parameters may indicate an associationbetween a search space set and a CORESET. A search space set maycomprise a set of PDCCH candidates formed by CCEs at a given aggregationlevel. The configuration parameters may indicate: a number of PDCCHcandidates to be monitored per aggregation level; a PDCCH monitoringperiodicity and a PDCCH monitoring pattern; one or more DCI formats tobe monitored by the UE; and/or whether a search space set is a commonsearch space set or a UE-specific search space set. A set of CCEs in thecommon search space set may be predefined and known to the UE. A set ofCCEs in the UE-specific search space set may be configured based on theUE's identity (e.g., C-RNTI).

As shown in FIG. 14B, the UE may determine a time-frequency resource fora CORESET based on RRC messages. The UE may determine a CCE-to-REGmapping (e.g., interleaved or non-interleaved, and/or mappingparameters) for the CORESET based on configuration parameters of theCORESET. The UE may determine a number (e.g., at most 10) of searchspace sets configured on the CORESET based on the RRC messages. The UEmay monitor a set of PDCCH candidates according to configurationparameters of a search space set. The UE may monitor a set of PDCCHcandidates in one or more CORESETs for detecting one or more DCIs.Monitoring may comprise decoding one or more PDCCH candidates of the setof the PDCCH candidates according to the monitored DCI formats.Monitoring may comprise decoding a DCI content of one or more PDCCHcandidates with possible (or configured) PDCCH locations, possible (orconfigured) PDCCH formats (e.g., number of CCEs, number of PDCCHcandidates in common search spaces, and/or number of PDCCH candidates inthe UE-specific search spaces) and possible (or configured) DCI formats.The decoding may be referred to as blind decoding. The UE may determinea DCI as valid for the UE, in response to CRC checking (e.g., scrambledbits for CRC parity bits of the DCI matching a RNTI value). The UE mayprocess information contained in the DCI (e.g., a scheduling assignment,an uplink grant, power control, a slot format indication, a downlinkpreemption, and/or the like).

The UE may transmit uplink control signaling (e.g., uplink controlinformation (UCI)) to a base station. The uplink control signaling maycomprise hybrid automatic repeat request (HARQ) acknowledgements forreceived DL-SCH transport blocks. The UE may transmit the HARQacknowledgements after receiving a DL-SCH transport block. Uplinkcontrol signaling may comprise channel state information (CSI)indicating channel quality of a physical downlink channel. The UE maytransmit the CSI to the base station. The base station, based on thereceived CSI, may determine transmission format parameters (e.g.,comprising multi-antenna and beamforming schemes) for a downlinktransmission. Uplink control signaling may comprise scheduling requests(SR). The UE may transmit an SR indicating that uplink data is availablefor transmission to the base station. The UE may transmit a UCI (e.g.,HARQ acknowledgements (HARQ-ACK), CSI report, SR, and the like) via aphysical uplink control channel (PUCCH) or a physical uplink sharedchannel (PUCCH). The UE may transmit the uplink control signaling via aPUCCH using one of several PUCCH formats.

There may be five PUCCH formats and the UE may determine a PUCCH formatbased on a size of the UCI (e.g., a number of uplink symbols of UCItransmission and a number of UCI bits). PUCCH format 0 may have a lengthof one or two OFDM symbols and may include two or fewer bits. The UE maytransmit UCI in a PUCCH resource using PUCCH format 0 if thetransmission is over one or two symbols and the number of HARQ-ACKinformation bits with positive or negative SR (HARQ-ACK/SR bits) is oneor two. PUCCH format 1 may occupy a number between four and fourteenOFDM symbols and may include two or fewer bits. The UE may use PUCCHformat 1 if the transmission is four or more symbols and the number ofHARQ-ACK/SR bits is one or two. PUCCH format 2 may occupy one or twoOFDM symbols and may include more than two bits. The UE may use PUCCHformat 2 if the transmission is over one or two symbols and the numberof UCI bits is two or more. PUCCH format 3 may occupy a number betweenfour and fourteen OFDM symbols and may include more than two bits. TheUE may use PUCCH format 3 if the transmission is four or more symbols,the number of UCI bits is two or more and PUCCH resource does notinclude an orthogonal cover code. PUCCH format 4 may occupy a numberbetween four and fourteen OFDM symbols and may include more than twobits. The UE may use PUCCH format 4 if the transmission is four or moresymbols, the number of UCI bits is two or more and the PUCCH resourceincludes an orthogonal cover code.

The base station may transmit configuration parameters to the UE for aplurality of PUCCH resource sets using, for example, an RRC message. Theplurality of PUCCH resource sets (e.g., up to four sets) may beconfigured on an uplink BWP of a cell. A PUCCH resource set may beconfigured with a PUCCH resource set index, a plurality of PUCCHresources with a PUCCH resource being identified by a PUCCH resourceidentifier (e.g., pucch-Resourceid), and/or a number (e.g. a maximumnumber) of UCI information bits the UE may transmit using one of theplurality of PUCCH resources in the PUCCH resource set. When configuredwith a plurality of PUCCH resource sets, the UE may select one of theplurality of PUCCH resource sets based on a total bit length of the UCIinformation bits (e.g., HARQ-ACK, SR, and/or CSI). If the total bitlength of UCI information bits is two or fewer, the UE may select afirst PUCCH resource set having a PUCCH resource set index equal to “0”.If the total bit length of UCI information bits is greater than two andless than or equal to a first configured value, the UE may select asecond PUCCH resource set having a PUCCH resource set index equal to“1”. If the total bit length of UCI information bits is greater than thefirst configured value and less than or equal to a second configuredvalue, the UE may select a third PUCCH resource set having a PUCCHresource set index equal to “2”. If the total bit length of UCIinformation bits is greater than the second configured value and lessthan or equal to a third value (e.g., 1406), the UE may select a fourthPUCCH resource set having a PUCCH resource set index equal to “3”.

After determining a PUCCH resource set from a plurality of PUCCHresource sets, the UE may determine a PUCCH resource from the PUCCHresource set for UCI (HARQ-ACK, CSI, and/or SR) transmission. The UE maydetermine the PUCCH resource based on a PUCCH resource indicator in aDCI (e.g., with a DCI format 1_0 or DCI for 1_1) received on a PDCCH. Athree-bit PUCCH resource indicator in the DCI may indicate one of eightPUCCH resources in the PUCCH resource set. Based on the PUCCH resourceindicator, the UE may transmit the UCI (HARQ-ACK, CSI and/or SR) using aPUCCH resource indicated by the PUCCH resource indicator in the DCI.

FIG. 15 illustrates an example of a wireless device 1502 incommunication with a base station 1504 in accordance with embodiments ofthe present disclosure. The wireless device 1502 and base station 1504may be part of a mobile communication network, such as the mobilecommunication network 100 illustrated in FIG. 1A, the mobilecommunication network 150 illustrated in FIG. 1B, or any othercommunication network. Only one wireless device 1502 and one basestation 1504 are illustrated in FIG. 15 , but it will be understood thata mobile communication network may include more than one UE and/or morethan one base station, with the same or similar configuration as thoseshown in FIG. 15 .

The base station 1504 may connect the wireless device 1502 to a corenetwork (not shown) through radio communications over the air interface(or radio interface) 1506. The communication direction from the basestation 1504 to the wireless device 1502 over the air interface 1506 isknown as the downlink, and the communication direction from the wirelessdevice 1502 to the base station 1504 over the air interface is known asthe uplink. Downlink transmissions may be separated from uplinktransmissions using FDD, TDD, and/or some combination of the twoduplexing techniques.

In the downlink, data to be sent to the wireless device 1502 from thebase station 1504 may be provided to the processing system 1508 of thebase station 1504. The data may be provided to the processing system1508 by, for example, a core network. In the uplink, data to be sent tothe base station 1504 from the wireless device 1502 may be provided tothe processing system 1518 of the wireless device 1502. The processingsystem 1508 and the processing system 1518 may implement layer 3 andlayer 2 OSI functionality to process the data for transmission. Layer 2may include an SDAP layer, a PDCP layer, an RLC layer, and a MAC layer,for example, with respect to FIG. 2A, FIG. 2B, FIG. 3 , and FIG. 4A.Layer 3 may include an RRC layer as with respect to FIG. 2B.

After being processed by processing system 1508, the data to be sent tothe wireless device 1502 may be provided to a transmission processingsystem 1510 of base station 1504. Similarly, after being processed bythe processing system 1518, the data to be sent to base station 1504 maybe provided to a transmission processing system 1520 of the wirelessdevice 1502. The transmission processing system 1510 and thetransmission processing system 1520 may implement layer 1 OSIfunctionality. Layer 1 may include a PHY layer with respect to FIG. 2A,FIG. 2B, FIG. 3 , and FIG. 4A. For transmit processing, the PHY layermay perform, for example, forward error correction coding of transportchannels, interleaving, rate matching, mapping of transport channels tophysical channels, modulation of physical channel, multiple-inputmultiple-output (MIMO) or multi-antenna processing, and/or the like.

At the base station 1504, a reception processing system 1512 may receivethe uplink transmission from the wireless device 1502. At the wirelessdevice 1502, a reception processing system 1522 may receive the downlinktransmission from base station 1504. The reception processing system1512 and the reception processing system 1522 may implement layer 1 OSIfunctionality. Layer 1 may include a PHY layer with respect to FIG. 2A,FIG. 2B, FIG. 3 , and FIG. 4A. For receive processing, the PHY layer mayperform, for example, error detection, forward error correctiondecoding, deinterleaving, demapping of transport channels to physicalchannels, demodulation of physical channels, MIMO or multi-antennaprocessing, and/or the like.

As shown in FIG. 15 , a wireless device 1502 and the base station 1504may include multiple antennas. The multiple antennas may be used toperform one or more MIMO or multi-antenna techniques, such as spatialmultiplexing (e.g., single-user MIMO or multi-user MIMO),transmit/receive diversity, and/or beamforming. In other examples, thewireless device 1502 and/or the base station 1504 may have a singleantenna.

The processing system 1508 and the processing system 1518 may beassociated with a memory 1514 and a memory 1524, respectively. Memory1514 and memory 1524 (e.g., one or more non-transitory computer readablemediums) may store computer program instructions or code that may beexecuted by the processing system 1508 and/or the processing system 1518to carry out one or more of the functionalities discussed in the presentapplication. Although not shown in FIG. 15 , the transmission processingsystem 1510, the transmission processing system 1520, the receptionprocessing system 1512, and/or the reception processing system 1522 maybe coupled to a memory (e.g., one or more non-transitory computerreadable mediums) storing computer program instructions or code that maybe executed to carry out one or more of their respectivefunctionalities.

The processing system 1508 and/or the processing system 1518 maycomprise one or more controllers and/or one or more processors. The oneor more controllers and/or one or more processors may comprise, forexample, a general-purpose processor, a digital signal processor (DSP),a microcontroller, an application specific integrated circuit (ASIC), afield programmable gate array (FPGA) and/or other programmable logicdevice, discrete gate and/or transistor logic, discrete hardwarecomponents, an on-board unit, or any combination thereof. The processingsystem 1508 and/or the processing system 1518 may perform at least oneof signal coding/processing, data processing, power control,input/output processing, and/or any other functionality that may enablethe wireless device 1502 and the base station 1504 to operate in awireless environment.

The processing system 1508 and/or the processing system 1518 may beconnected to one or more peripherals 1516 and one or more peripherals1526, respectively. The one or more peripherals 1516 and the one or moreperipherals 1526 may include software and/or hardware that providefeatures and/or functionalities, for example, a speaker, a microphone, akeypad, a display, a touchpad, a power source, a satellite transceiver,a universal serial bus (USB) port, a hands-free headset, a frequencymodulated (FM) radio unit, a media player, an Internet browser, anelectronic control unit (e.g., for a motor vehicle), and/or one or moresensors (e.g., an accelerometer, a gyroscope, a temperature sensor, aradar sensor, a lidar sensor, an ultrasonic sensor, a light sensor, acamera, and/or the like). The processing system 1508 and/or theprocessing system 1518 may receive user input data from and/or provideuser output data to the one or more peripherals 1516 and/or the one ormore peripherals 1526. The processing system 1518 in the wireless device1502 may receive power from a power source and/or may be configured todistribute the power to the other components in the wireless device1502. The power source may comprise one or more sources of power, forexample, a battery, a solar cell, a fuel cell, or any combinationthereof. The processing system 1508 and/or the processing system 1518may be connected to a GPS chipset 1517 and a GPS chipset 1527,respectively. The GPS chipset 1517 and the GPS chipset 1527 may beconfigured to provide geographic location information of the wirelessdevice 1502 and the base station 1504, respectively.

FIG. 16A illustrates an example structure for uplink transmission. Abaseband signal representing a physical uplink shared channel mayperform one or more functions. The one or more functions may comprise atleast one of: scrambling; modulation of scrambled bits to generatecomplex-valued symbols; mapping of the complex-valued modulation symbolsonto one or several transmission layers; transform precoding to generatecomplex-valued symbols; precoding of the complex-valued symbols; mappingof precoded complex-valued symbols to resource elements; generation ofcomplex-valued time-domain Single Carrier-Frequency Division MultipleAccess (SC-FDMA) or CP-OFDM signal for an antenna port; and/or the like.In an example, when transform precoding is enabled, a SC-FDMA signal foruplink transmission may be generated. In an example, when transformprecoding is not enabled, an CP-OFDM signal for uplink transmission maybe generated by FIG. 16A. These functions are illustrated as examplesand it is anticipated that other mechanisms may be implemented invarious embodiments.

FIG. 16B illustrates an example structure for modulation andup-conversion of a baseband signal to a carrier frequency. The basebandsignal may be a complex-valued SC-FDMA or CP-OFDM baseband signal for anantenna port and/or a complex-valued Physical Random Access Channel(PRACH) baseband signal. Filtering may be employed prior totransmission.

FIG. 16C illustrates an example structure for downlink transmissions. Abaseband signal representing a physical downlink channel may perform oneor more functions. The one or more functions may comprise: scrambling ofcoded bits in a codeword to be transmitted on a physical channel;modulation of scrambled bits to generate complex-valued modulationsymbols; mapping of the complex-valued modulation symbols onto one orseveral transmission layers; precoding of the complex-valued modulationsymbols on a layer for transmission on the antenna ports; mapping ofcomplex-valued modulation symbols for an antenna port to resourceelements; generation of complex-valued time-domain OFDM signal for anantenna port; and/or the like. These functions are illustrated asexamples and it is anticipated that other mechanisms may be implementedin various embodiments.

FIG. 16D illustrates another example structure for modulation andup-conversion of a baseband signal to a carrier frequency. The basebandsignal may be a complex-valued OFDM baseband signal for an antenna port.Filtering may be employed prior to transmission.

A wireless device may receive from a base station one or more messages(e.g. RRC messages) comprising configuration parameters of a pluralityof cells (e.g. primary cell, secondary cell). The wireless device maycommunicate with at least one base station (e.g. two or more basestations in dual-connectivity) via the plurality of cells. The one ormore messages (e.g. as a part of the configuration parameters) maycomprise parameters of physical, MAC, RLC, PCDP, SDAP, RRC layers forconfiguring the wireless device. For example, the configurationparameters may comprise parameters for configuring physical and MAClayer channels, bearers, etc. For example, the configuration parametersmay comprise parameters indicating values of timers for physical, MAC,RLC, PCDP, SDAP, RRC layers, and/or communication channels.

A timer may begin running once it is started and continue running untilit is stopped or until it expires. A timer may be started if it is notrunning or restarted if it is running. A timer may be associated with avalue (e.g. the timer may be started or restarted from a value or may bestarted from zero and expire once it reaches the value). The duration ofa timer may not be updated until the timer is stopped or expires (e.g.,due to BWP switching). A timer may be used to measure a timeperiod/window for a process. When the specification refers to animplementation and procedure related to one or more timers, it will beunderstood that there are multiple ways to implement the one or moretimers. For example, it will be understood that one or more of themultiple ways to implement a timer may be used to measure a timeperiod/window for the procedure. For example, a random access responsewindow timer may be used for measuring a window of time for receiving arandom access response. In an example, instead of starting and expiry ofa random access response window timer, the time difference between twotime stamps may be used. When a timer is restarted, a process formeasurement of time window may be restarted. Other exampleimplementations may be provided to restart a measurement of a timewindow.

A base station may transmit one or more MAC PDUs to a wireless device.In an example, a MAC PDU may be a bit string that is byte aligned (e.g.,aligned to a multiple of eight bits) in length. In an example, bitstrings may be represented by tables in which the most significant bitis the leftmost bit of the first line of the table, and the leastsignificant bit is the rightmost bit on the last line of the table. Moregenerally, the bit string may be read from left to right and then in thereading order of the lines. In an example, the bit order of a parameterfield within a MAC PDU is represented with the first and mostsignificant bit in the leftmost bit and the last and least significantbit in the rightmost bit.

In an example, a MAC SDU may be a bit string that is byte aligned (e.g.,aligned to a multiple of eight bits) in length. In an example, a MAC SDUmay be included in a MAC PDU from the first bit onward. A MAC CE may bea bit string that is byte aligned (e.g., aligned to a multiple of eightbits) in length. A MAC subheader may be a bit string that is bytealigned (e.g., aligned to a multiple of eight bits) in length. In anexample, a MAC subheader may be placed immediately in front of acorresponding MAC SDU, MAC CE, or padding. A MAC entity may ignore avalue of reserved bits in a DL MAC PDU.

In an example, a MAC PDU may comprise one or more MAC subPDUs. A MACsubPDU of the one or more MAC subPDUs may comprise: a MAC subheader only(including padding); a MAC subheader and a MAC SDU; a MAC subheader anda MAC CE; a MAC subheader and padding, or a combination thereof. The MACSDU may be of variable size. A MAC subheader may correspond to a MACSDU, a MAC CE, or padding.

In an example, when a MAC subheader corresponds to a MAC SDU, avariable-sized MAC CE, or padding, the MAC subheader may comprise: an Rfield with a one bit length; an F field with a one-bit length; an LCIDfield with a multi-bit length; an L field with a multi-bit length, or acombination thereof.

FIG. 17A shows an example of a MAC subheader with an R field, an Ffield, an LCID field, and an L field. In the example MAC subheader ofFIG. 17A, the LCID field may be six bits in length, and the L field maybe eight bits in length. FIG. 17B shows example of a MAC subheader withan R field, a F field, an LCID field, and an L field. In the example MACsubheader shown in FIG. 17B, the LCID field may be six bits in length,and the L field may be sixteen bits in length. When a MAC subheadercorresponds to a fixed sized MAC CE or padding, the MAC subheader maycomprise: a R field with a two-bit length and an LCID field with amulti-bit length. FIG. 17C shows an example of a MAC subheader with an Rfield and an LCID field. In the example MAC subheader shown in FIG. 17C,the LCID field may be six bits in length, and the R field may be twobits in length.

FIG. 18A shows an example of a DL MAC PDU. Multiple MAC CEs, such as MACCE 1 and 2, may be placed together. A MAC subPDU, comprising a MAC CE,may be placed before: a MAC subPDU comprising a MAC SDU, or a MAC subPDUcomprising padding. FIG. 18B shows an example of a UL MAC PDU. MultipleMAC CEs, such as MAC CE 1 and 2, may be placed together. In anembodiment, a MAC subPDU comprising a MAC CE may be placed after all MACsubPDUs comprising a MAC SDU. In addition, the MAC subPDU may be placedbefore a MAC subPDU comprising padding.

In an example, a MAC entity of a base station may transmit one or moreMAC CEs to a MAC entity of a wireless device. FIG. 19 shows an exampleof multiple LCIDs that may be associated with the one or more MAC CEs.The one or more MAC CEs comprise at least one of: a SP ZP CSI-RSResource Set Activation/Deactivation MAC CE, a PUCCH spatial relationActivation/Deactivation MAC CE, a SP SRS Activation/Deactivation MAC CE,a SP CSI reporting on PUCCH Activation/Deactivation MAC CE, a TCI StateIndication for UE-specific PDCCH MAC CE, a TCI State Indication forUE-specific PDSCH MAC CE, an Aperiodic CSI Trigger State SubselectionMAC CE, a SP CSI-RS/CSI-IM Resource Set Activation/Deactivation MAC CE,a UE contention resolution identity MAC CE, a timing advance command MACCE, a DRX command MAC CE, a Long DRX command MAC CE, an SCellactivation/deactivation MAC CE (1 Octet), an SCellactivation/deactivation MAC CE (4 Octet), and/or a duplicationactivation/deactivation MAC CE. In an example, a MAC CE, such as a MACCE transmitted by a MAC entity of a base station to a MAC entity of awireless device, may have an LCID in the MAC subheader corresponding tothe MAC CE. Different MAC CE may have different LCID in the MACsubheader corresponding to the MAC CE. For example, an LCID given by111011 in a MAC subheader may indicate that a MAC CE associated with theMAC subheader is a long DRX command MAC CE.

In an example, the MAC entity of the wireless device may transmit to theMAC entity of the base station one or more MAC CEs. FIG. 20 shows anexample of the one or more MAC CEs. The one or more MAC CEs may compriseat least one of: a short buffer status report (BSR) MAC CE, a long BSRMAC CE, a C-RNTI MAC CE, a configured grant confirmation MAC CE, asingle entry PHR MAC CE, a multiple entry PHR MAC CE, a short truncatedBSR, and/or a long truncated BSR. In an example, a MAC CE may have anLCID in the MAC subheader corresponding to the MAC CE. Different MAC CEmay have different LCID in the MAC subheader corresponding to the MACCE. For example, an LCID given by 111011 in a MAC subheader may indicatethat a MAC CE associated with the MAC subheader is a short-truncatedcommand MAC CE.

In carrier aggregation (CA), two or more component carriers (CCs) may beaggregated. A wireless device may simultaneously receive or transmit onone or more CCs, depending on capabilities of the wireless device, usingthe technique of CA. In an embodiment, a wireless device may support CAfor contiguous CCs and/or for non-contiguous CCs. CCs may be organizedinto cells. For example, CCs may be organized into one primary cell(PCell) and one or more secondary cells (SCells). When configured withCA, a wireless device may have one RRC connection with a network. Duringan RRC connection establishment/re-establishment/handover, a cellproviding NAS mobility information may be a serving cell. During an RRCconnection re-establishment/handover procedure, a cell providing asecurity input may be a serving cell. In an example, the serving cellmay denote a PCell. In an example, a base station may transmit, to awireless device, one or more messages comprising configurationparameters of a plurality of one or more SCells, depending oncapabilities of the wireless device.

When configured with CA, a base station and/or a wireless device mayemploy an activation/deactivation mechanism of an SCell to improvebattery or power consumption of the wireless device. When a wirelessdevice is configured with one or more SCells, a base station mayactivate or deactivate at least one of the one or more SCells. Uponconfiguration of an SCell, the SCell may be deactivated unless an SCellstate associated with the SCell is set to “activated” or “dormant”.

A wireless device may activate/deactivate an SCell in response toreceiving an SCell Activation/Deactivation MAC CE. In an example, a basestation may transmit, to a wireless device, one or more messagescomprising an SCell timer (e.g., sCellDeactivationTimer). In an example,a wireless device may deactivate an SCell in response to an expiry ofthe SCell timer.

When a wireless device receives an SCell Activation/Deactivation MAC CEactivating an SCell, the wireless device may activate the SCell. Inresponse to the activating the SCell, the wireless device may performoperations comprising SRS transmissions on the SCell; CQI/PMI/RI/CRIreporting for the SCell; PDCCH monitoring on the SCell; PDCCH monitoringfor the SCell; and/or PUCCH transmissions on the SCell. In response tothe activating the SCell, the wireless device may start or restart afirst SCell timer (e.g., sCellDeactivationTimer) associated with theSCell. The wireless device may start or restart the first SCell timer inthe slot when the SCell Activation/Deactivation MAC CE activating theSCell has been received. In an example, in response to the activatingthe SCell, the wireless device may (re-)initialize one or more suspendedconfigured uplink grants of a configured grant Type 1 associated withthe SCell according to a stored configuration. In an example, inresponse to the activating the SCell, the wireless device may triggerPHR.

When a wireless device receives an SCell Activation/Deactivation MAC CEdeactivating an activated SCell, the wireless device may deactivate theactivated SCell. In an example, when a first SCell timer (e.g.,sCellDeactivationTimer) associated with an activated SCell expires, thewireless device may deactivate the activated SCell. In response to thedeactivating the activated SCell, the wireless device may stop the firstSCell timer associated with the activated SCell. In an example, inresponse to the deactivating the activated SCell, the wireless devicemay clear one or more configured downlink assignments and/or one or moreconfigured uplink grants of a configured uplink grant Type 2 associatedwith the activated SCell. In an example, in response to the deactivatingthe activated SCell, the wireless device may: suspend one or moreconfigured uplink grants of a configured uplink grant Type 1 associatedwith the activated SCell; and/or flush HARQ buffers associated with theactivated SCell.

When an SCell is deactivated, a wireless device may not performoperations comprising: transmitting SRS on the SCell; reportingCQI/PMI/RI/CRI for the SCell; transmitting on UL-SCH on the SCell;transmitting on RACH on the SCell; monitoring at least one first PDCCHon the SCell; monitoring at least one second PDCCH for the SCell; and/ortransmitting a PUCCH on the SCell. When at least one first PDCCH on anactivated SCell indicates an uplink grant or a downlink assignment, awireless device may restart a first SCell timer (e.g.,sCellDeactivationTimer) associated with the activated SCell. In anexample, when at least one second PDCCH on a serving cell (e.g., a PCellor an SCell configured with PUCCH, i.e., PUCCH SCell) scheduling theactivated SCell indicates an uplink grant or a downlink assignment forthe activated SCell, a wireless device may restart the first SCell timer(e.g., sCellDeactivationTimer) associated with the activated SCell. Inan example, when an SCell is deactivated, if there is an ongoing randomaccess procedure on the SCell, a wireless device may abort the ongoingrandom access procedure on the SCell.

FIG. 21A shows an example of an SCell Activation/Deactivation MAC CE ofone octet. A first MAC PDU subheader with a first LCID (e.g., ‘111010’as shown in FIG. 19 ) may identify the SCell Activation/Deactivation MACCE of one octet. The SCell Activation/Deactivation MAC CE of one octetmay have a fixed size. The SCell Activation/Deactivation MAC CE of oneoctet may comprise a single octet. The single octet may comprise a firstnumber of C-fields (e.g., seven) and a second number of R-fields (e.g.,one).

FIG. 21B shows an example of an SCell Activation/Deactivation MAC CE offour octets. A second MAC PDU subheader with a second LCID (e.g.,‘111001’ as shown in FIG. 19 ) may identify the SCellActivation/Deactivation MAC CE of four octets. The SCellActivation/Deactivation MAC CE of four octets may have a fixed size. TheSCell Activation/Deactivation MAC CE of four octets may comprise fouroctets. The four octets may comprise a third number of C-fields (e.g.,31) and a fourth number of R-fields (e.g., 1).

In FIG. 21A and/or FIG. 21B, a C_(i) field may indicate anactivation/deactivation status of an SCell with an SCell index i if anSCell with SCell index i is configured. In an example, when the C_(i)field is set to one, an SCell with an SCell index i may be activated. Inan example, when the C_(i) field is set to zero, an SCell with an SCellindex i may be deactivated. In an example, if there is no SCellconfigured with SCell index i, the wireless device may ignore the C_(i)field. In FIG. 21A and FIG. 21B, an R field may indicate a reserved bit.The R field may be set to zero.

FIG. 22A shows an example embodiment of RRC configuration of parametersof power saving operation and/or a DRX operation. In an example, a basestation may transmit to a wireless device one or more RRC messagescomprising configuration parameters of DRX operation. A MAC entity ofthe wireless device, based on the configuration parameters of the DRXoperation, may control PDCCH monitoring activity of the MAC entity'sC-RNTI, CI-RNTI, CS-RNTI, INT-RNTI, SFI-RNTI, SP-CSI-RNTI,TPC-PUCCH-RNTI, TPC-PUSCH-RNTI, TPC-SRS-RNTI, and Al-RNTI. When inRRC_CONNECTED, if DRX is configured, for all the activated ServingCells, the MAC entity may monitor the PDCCH discontinuously using theDRX operation. Otherwise, the MAC entity may monitor the PDCCHcontinuously.

In an example, the configuration parameters of the DRX operation maycomprise: drx-onDurationTimer indicating a duration at the beginning ofa DRX cycle, drx-SlotOffset indicating a delay before starting thedrx-onDurationTimer, drx-InactivityTimer indicating a duration after aPDCCH occasion in which a PDCCH indicates a new UL or DL transmissionfor the MAC entity, drx-RetransmissionTimerDL (per DL HARQ processexcept for the broadcast process) indicating a maximum duration until aDL retransmission is received, drx-RetransmissionTimerUL (per UL HARQprocess) indicating a maximum duration until a grant for ULretransmission is received, drx-LongCycleStartOffset indicating a LongDRX cycle and drx-StartOffset which defines a subframe where a Long andShort DRX cycle starts, drx-ShortCycle for a Short DRX cycle,drx-ShortCycleTimer indicating a duration the wireless device may followthe Short DRX cycle, drx-HARQ-RTT-TimerDL (per DL HARQ process exceptfor the broadcast process) indicating a minimum duration before a DLassignment for HARQ retransmission is expected by the MAC entity,drx-HARQ-RTT-TimerUL (per UL HARQ process) indicating a minimum durationbefore a UL HARQ retransmission grant is expected by the MAC entity.

In an example, configuration parameters of a power saving operation(e.g., associated with a DRX operation) may comprise: ps-Wakeupindicating whether to start associated drx-onDurationTimer in case a DCIwith CRC scrambled by a PS-RNTI (DCP) is monitored but not detected bythe wireless device, ps-TransmitOtherPeriodicCSI indicating whether toreport periodic CSI that is not L1-RSRP on PUCCH during the timeduration indicated by drx-onDurationTimer in case the DCP is configuredbut associated drx-onDurationTimer is not started,ps-TransmitPeriodicL1-RSRP indicating whether to transmit periodic CSIthat is L1-RSRP on PUCCH during the time duration indicated bydrx-onDurationTimer in case the DCP is configured but associateddrx-onDurationTimer is not started.

In an example, the configuration parameters of the power savingoperation may comprise: ps-RNTI indicating a PS-RNTI for DCI format 2_6(e.g., based on example embodiment of FIG. 24 ), dci-Format2-6indicating a number of search space sets for monitoring PDCCH fordetection of DCI format 2_6 on an active DL BWP of the PCell or of theSpCell according to a common search space, size-DCI-2-6 indicating apayload size for DCI format 2_6. The configuration parameters maycomprise ps-PositionDCI-2-6 indicating a location in DCI format 2_6 of aWake-up indication bit wherein the Wake-up indication bit setting to 0,when reported to higher layers, indicates to not start thedrx-onDurationTimer for the next long DRX cycle, or the Wake-upindication bit setting to 1, when reported to higher layers, indicatesstart the drx-onDurationTimer for the next long DRX cycle.

In an example, if a wireless device is provided search space sets tomonitor PDCCH for detection of DCI format 2_6 in the active DL BWP ofthe PCell or of the SpCell and the UE detects DCI format 2_6, thephysical layer of the wireless device reports the value of the Wake-upindication bit for the wireless device to higher layers (e.g., MACentity/layer of the wireless device) for the next long DRX cycle. If thewireless device does not detect DCI format 2_6, the physical layer ofthe wireless device does not report a value of the Wake-up indicationbit to higher layers for the next long DRX cycle.

In an example, if a wireless device is provided search space sets tomonitor PDCCH for detection of DCI format 2_6 in the active DL BWP ofthe PCell or of the SpCell and the wireless device is not required tomonitor PDCCH for detection of DCI format 2_6 for all correspondingPDCCH monitoring occasions outside Active Time prior to a next long DRXcycle, or does not have any PDCCH monitoring occasions for detection ofDCI format 2_6 outside Active Time of a next long DRX cycle, thephysical layer of the wireless device reports a value of 1 for theWake-up indication bit to higher layers for the next long DRX cycle.

In an example, Serving Cells of a MAC entity may be configured by RRC intwo DRX groups with separate DRX parameters. When RRC does not configurea secondary DRX group, there may be only one DRX group and all ServingCells belong to that one DRX group. When two DRX groups are configured,each Serving Cell is uniquely assigned to either of the two groups. TheDRX parameters that are separately configured for each DRX group are:drx-onDurationTimer, drx-InactivityTimer. The DRX parameters that arecommon to the DRX groups are: drx-SlotOffset, drx-RetransmissionTimerDL,drx-RetransmissionTimerUL, drx-LongCycleStartOffset, drx-ShortCycle(optional), drx-ShortCycleTimer (optional), drx-HARQ-RTT-TimerDL, anddrx-HARQ-RTT-TimerUL.

In an example, when a DRX cycle is configured, a wireless device maydetermine that the Active Time for Serving Cells in a DRX group includesthe time while: drx-onDurationTimer or drx-InactivityTimer configuredfor the DRX group is running, or drx-RetransmissionTimerDL ordrx-RetransmissionTimerUL is running on any Serving Cell in the DRXgroup, or ra-ContentionResolutionTimer (or msgB-ResponseWindow) isrunning, or a SR is sent on PUCCH and is pending; a PDCCH indicating anew transmission addressed to the C-RNTI of the MAC entity has not beenreceived after successful reception of a RAR for the Random AccessPreamble not selected by the MAC entity among the contention-basedRandom Access Preamble.

In an example, when DRX operation is configured, if a MAC PDU isreceived in a configured downlink assignment, a MAC entity of a wirelessdevice may start the drx-HARQ-RTT-TimerDL for a corresponding HARQprocess in a first symbol after the end of a corresponding transmissioncarrying a DL HARQ feedback and/or stop the drx-RetransmissionTimerDLfor the corresponding HARQ process.

In an example, when DRX operation is configured, if a MAC PDU istransmitted in a configured uplink grant and LBT failure indication isnot received from lower layers, a MAC entity of a wireless device maystart the drx-HARQ-RTT-TimerUL for the corresponding HARQ process in thefirst symbol after the end of the first transmission (e.g., within abundle) of the corresponding PUSCH transmission and/or stop thedrx-RetransmissionTimerUL for the corresponding HARQ process at thefirst transmission (within a bundle) of the corresponding PUSCHtransmission.

In an example, when DRX operation is configured, if adrx-HARQ-RTT-TimerDL expires and if the data of the corresponding HARQprocess was not successfully decoded, a MAC entity of a wireless devicemay start the drx-RetransmissionTimerDL for the corresponding HARQprocess in the first symbol after the expiry of drx-HARQ-RTT-TimerDL.

In an example, when DRX operation is configured, if adrx-HARQ-RTT-TimerUL expires, a MAC entity of a wireless device maystart the drx-RetransmissionTimerUL for the corresponding HARQ processin the first symbol after the expiry of drx-HARQ-RTT-TimerUL.

In an example, when DRX operation is configured, if a DRX Command MAC CEor a Long DRX Command MAC CE is received, a MAC entity of a wirelessdevice may stop drx-onDurationTimer for each DRX group and/or stopdrx-InactivityTimer for each DRX group.

In an example, when DRX operation is configured, if drx-InactivityTimerfor a DRX group expires, a MAC entity of a wireless device may start orrestart drx-ShortCycleTimer for this DRX group in the first symbol afterthe expiry of drx-InactivityTimer and/or use the Short DRX cycle forthis DRX group, if the Short DRX cycle is configured. Ifdrx-InactivityTimer for a DRX group expires, a MAC entity of a wirelessdevice may use the Long DRX cycle for this DRX group, if the Short DRXcycle is not configured.

In an example, when DRX operation is configured, if a DRX Command MAC CEis received, a MAC entity of a wireless device may start or restartdrx-ShortCycleTimer for each DRX group in the first symbol after the endof DRX Command MAC CE reception and/or use the Short DRX cycle for eachDRX group, if the Short DRX cycle is configured. If a DRX Command MAC CEis received, a MAC entity of a wireless device may use the Long DRXcycle for this DRX group, if the Short DRX cycle is not configured.

In an example, when DRX operation is configured, if drx-ShortCycleTimerfor a DRX group expires, a MAC entity of a wireless device may use theLong DRX cycle for this DRX group. If a Long DRX Command MAC CE isreceived, a MAC entity of a wireless device may stop drx-ShortCycleTimerfor each DRX group and/or use the Long DRX cycle for each DRX group.

In an example, when DRX operation is configured, if the Short DRX cycleis used for a DRX group, and [(SFN×10)+subframe number] modulo(drx-ShortCycle)=(drx-StartOffset) modulo (drx-ShortCycle), a MAC entityof a wireless device may start drx-onDurationTimer for this DRX groupafter drx-SlotOffset from the beginning of the subframe.

FIG. 22B shows an example embodiment of a power saving operation basedon DCP reception. In an example, when a wireless device receives a DCPcomprising a wake-up indication being set to a first value, the wirelessdevice may start a drx-onDurationTimer associated with the DRX operationand/or monitor PDCCH during the drx-onDurationTimer being running. whenthe drx-onDurationTimer expires (or the DRX switching to a DRX offduration), the wireless device may stop monitoring the PDCCH. In anexample, when a wireless device receives a DCP comprising a wake-upindication being set to a second value, the wireless device may notstart a drx-onDurationTimer associated with the DRX operation and/orskip monitoring PDCCH for the DRX on duration.

In an example embodiment, when DRX operation is configured, if the LongDRX cycle is used for a DRX group, and [(SFN×10)+subframe number] modulo(drx-LongCycle)=drx-StartOffset and if DCP monitoring is configured forthe active DL BWP, a MAC entity of a wireless device may startdrx-onDurationTimer after drx-SlotOffset from the beginning of thesubframe, if DCP indication associated with the current DRX cyclereceived from lower layer indicated to start drx-onDurationTimer, or ifall DCP occasion(s) in time domain, associated with the current DRXcycle occurred in Active Time considering grants/assignments/DRX CommandMAC CE/Long DRX Command MAC CE received and Scheduling Request sentuntil 4 ms prior to start of the last DCP occasion, or during ameasurement gap, or when the MAC entity monitors for a PDCCHtransmission on the search space indicated by recoverySearchSpaceId ofthe SpCell identified by the C-RNTI while the ra-ResponseWindow isrunning, or if ps-Wakeup is configured with value true and DCPindication associated with the current DRX cycle has not been receivedfrom lower layers.

In an example, when DRX operation is configured, if the Long DRX cycleis used for a DRX group, and [(SFN×10)+subframe number] modulo(drx-LongCycle)=drx-StartOffset and if DCP monitoring is not configuredfor the active DL BWP, a MAC entity of a wireless device may startdrx-onDurationTimer for this DRX group after drx-SlotOffset from thebeginning of the subframe.

In an example, when DRX operation is configured, if a DRX group is inActive Time, a MAC entity of a wireless device may monitor the PDCCH onthe Serving Cells in this DRX group. If the PDCCH indicates a DLtransmission, the MAC entity of a wireless device may start thedrx-HARQ-RTT-TimerDL for the corresponding HARQ process in the firstsymbol after the end of the corresponding transmission carrying the DLHARQ feedback and/or stop the drx-RetransmissionTimerDL for thecorresponding HARQ process. The MAC entity may start thedrx-RetransmissionTimerDL in the first symbol after the PDSCHtransmission for the corresponding HARQ process if thePDSCH-to-HARQ_feedback timing indicate a non-numerical k1 value. WhenHARQ feedback is postponed by PDSCH-to-HARQ_feedback timing indicating anon-numerical k1 value, the corresponding transmission opportunity tosend the DL HARQ feedback is indicated in a later PDCCH requesting theHARQ-ACK feedback.

In an example, when DRX operation is configured, if a DRX group is inActive Time, a MAC entity of a wireless device may monitor the PDCCH onthe Serving Cells in this DRX group. If the PDCCH indicates a ULtransmission, the MAC entity may start the drx-HARQ-RTT-TimerUL for thecorresponding HARQ process in the first symbol after the end of thefirst transmission (within a bundle) of the corresponding PUSCHtransmission and/or stop the drx-RetransmissionTimerUL for thecorresponding HARQ process.

In an example, when DRX operation is configured, if a DRX group is inActive Time, a MAC entity of a wireless device may monitor the PDCCH onthe Serving Cells in this DRX group. If the PDCCH indicates a newtransmission (DL or UL) on a Serving Cell in this DRX group, the MACentity may start or restart drx-InactivityTimer for this DRX group inthe first symbol after the end of the PDCCH reception. If a HARQ processreceives downlink feedback information and acknowledgement is indicated,the MAC entity may stop the drx-RetransmissionTimerUL for thecorresponding HARQ process.

In an example, when DRX operation is configured, if DCP monitoring isconfigured for the active DL BWP and if the current symbol n occurswithin drx-onDurationTimer duration and if drx-onDurationTimerassociated with the current DRX cycle is not started, if the MAC entitywould not be in Active Time considering grants/assignments/DRX CommandMAC CE/Long DRX Command MAC CE received and SR sent until 4 ms prior tosymbol n when evaluating all DRX Active Time conditions: the MAC entityshould not transmit periodic SRS and semi-persistent SRS, not reportsemi-persistent CSI configured on PUSCH, not report periodic CSI that isL1-RSRP on PUCCH if ps-TransmitPeriodicL1-RSRP is not configured withvalue true, not report periodic CSI that is not L1-RSRP on PUCCH ifps-TransmitOtherPeriodicCSI is not configured with value true.

In an example, when DRX operation is configured, if DCP monitoring isnot configured for the active DL BWP, and/or if the current symbol noccurs not within drx-onDurationTimer duration, and/or ifdrx-onDurationTimer associated with the current DRX cycle is started, incurrent symbol n, if a DRX group would not be in Active Time consideringgrants/assignments scheduled on Serving Cell(s) in this DRX group andDRX Command MAC CE/Long DRX Command MAC CE received and SchedulingRequest sent until 4 ms prior to symbol n when evaluating all DRX ActiveTime conditions: the MAC entity should not transmit periodic SRS andsemi-persistent SRS in this DRX group, not report CSI on PUCCH andsemi-persistent CSI configured on PUSCH in this DRX group, not reportCSI on PUCCH in this DRX group if CSI masking (csi-Mask) is setup byupper layers and in current symbol n, if drx-onDurationTimer of a DRXgroup would not be running considering grants/assignments scheduled onServing Cell(s) in this DRX group and DRX Command MAC CE/Long DRXCommand MAC CE received until 4 ms prior to symbol n when evaluating allDRX Active Time conditions.

In an example, regardless of whether the MAC entity is monitoring PDCCHor not on the Serving Cells in a DRX group, the MAC entity may transmitHARQ feedback, aperiodic CSI on PUSCH, and aperiodic SRS on the ServingCells in the DRX group when such is expected. The MAC entity needs notto monitor the PDCCH if it is not a complete PDCCH occasion (e.g. theActive Time starts or ends in the middle of a PDCCH occasion).

A base station may configure a wireless device with uplink (UL)bandwidth parts (BWPs) and downlink (DL) BWPs to enable bandwidthadaptation (BA) on a PCell. If carrier aggregation is configured, thebase station may further configure the wireless device with at least DLBWP(s) (i.e., there may be no UL BWPs in the UL) to enable BA on anSCell. For the PCell, an initial active BWP may be a first BWP used forinitial access. For the SCell, a first active BWP may be a second BWPconfigured for the wireless device to operate on the SCell upon theSCell being activated. In paired spectrum (e.g., FDD), a base stationand/or a wireless device may independently switch a DL BWP and an ULBWP. In unpaired spectrum (e.g., TDD), a base station and/or a wirelessdevice may simultaneously switch a DL BWP and an UL BWP.

In an example, a base station and/or a wireless device may switch a BWPbetween configured BWPs by means of a DCI or a BWP inactivity timer.When the BWP inactivity timer is configured for a serving cell, the basestation and/or the wireless device may switch an active BWP to a defaultBWP in response to an expiry of the BWP inactivity timer associated withthe serving cell. The default BWP may be configured by the network. Inan example, for FDD systems, when configured with BA, one UL BWP foreach uplink carrier and one DL BWP may be active at a time in an activeserving cell. In an example, for TDD systems, one DL/UL BWP pair may beactive at a time in an active serving cell. Operating on the one UL BWPand the one DL BWP (or the one DL/UL pair) may improve wireless devicebattery consumption. BWPs other than the one active UL BWP and the oneactive DL BWP that the wireless device may work on may be deactivated.On deactivated BWPs, the wireless device may: not monitor PDCCH; and/ornot transmit on PUCCH, PRACH, and UL-SCH.

In an example, a serving cell may be configured with at most a firstnumber (e.g., four) of BWPs. In an example, for an activated servingcell, there may be one active BWP at any point in time. In an example, aBWP switching for a serving cell may be used to activate an inactive BWPand deactivate an active BWP at a time. In an example, the BWP switchingmay be controlled by a PDCCH indicating a downlink assignment or anuplink grant. In an example, the BWP switching may be controlled by aBWP inactivity timer (e.g., bwp-InactivityTimer). In an example, the BWPswitching may be controlled by a MAC entity in response to initiating aRandom Access procedure. Upon addition of an SpCell or activation of anSCell, one BWP may be initially active without receiving a PDCCHindicating a downlink assignment or an uplink grant. The active BWP fora serving cell may be indicated by RRC and/or PDCCH. In an example, forunpaired spectrum, a DL BWP may be paired with a UL BWP, and BWPswitching may be common for both UL and DL.

FIG. 23 shows an example of BWP switching on a cell (e.g., PCell orSCell). In an example, a wireless device may receive, from a basestation, at least one RRC message comprising parameters of a cell andone or more BWPs associated with the cell. The RRC message may comprise:RRC connection reconfiguration message (e.g., RRCReconfiguration); RRCconnection reestablishment message (e.g., RRCRestablishment); and/or RRCconnection setup message (e.g., RRCSetup). Among the one or more BWPs,at least one BWP may be configured as the first active BWP (e.g., BWP1), one BWP as the default BWP (e.g., BWP 0). The wireless device mayreceive a command (e.g., RRC message, MAC CE or DCI) to activate thecell at an nth slot. In case the cell is a PCell, the wireless devicemay not receive the command activating the cell, for example, thewireless device may activate the PCell once the wireless device receivesRRC message comprising configuration parameters of the PCell. Thewireless device may start monitoring a PDCCH on BWP 1 in response toactivating the cell.

In an example, the wireless device may start (or restart) a BWPinactivity timer (e.g., bwp-InactivityTimer) at an mth slot in responseto receiving a DCI indicating DL assignment on BWP 1. The wirelessdevice may switch back to the default BWP (e.g., BWP 0) as an active BWPwhen the BWP inactivity timer expires, at sth slot. The wireless devicemay deactivate the cell and/or stop the BWP inactivity timer when thesCellDeactivationTimer expires (e.g., if the cell is a SCell). Inresponse to the cell being a PCell, the wireless device may notdeactivate the cell and may not apply the sCellDeactivationTimer on thePCell.

In an example, a MAC entity may apply normal operations on an active BWPfor an activated serving cell configured with a BWP comprising:transmitting on UL-SCH; transmitting on RACH; monitoring a PDCCH;transmitting PUCCH; receiving DL-SCH; and/or (re-) initializing anysuspended configured uplink grants of configured grant Type 1 accordingto a stored configuration, if any.

In an example, on an inactive BWP for each activated serving cellconfigured with a BWP, a MAC entity may: not transmit on UL-SCH; nottransmit on RACH; not monitor a PDCCH; not transmit PUCCH; not transmitSRS, not receive DL-SCH; clear any configured downlink assignment andconfigured uplink grant of configured grant Type 2; and/or suspend anyconfigured uplink grant of configured Type 1.

In an example, if a MAC entity receives a PDCCH for a BWP switching of aserving cell while a Random Access procedure associated with thisserving cell is not ongoing, a wireless device may perform the BWPswitching to a BWP indicated by the PDCCH. In an example, if a bandwidthpart indicator field is configured in DCI format 1_1, the bandwidth partindicator field value may indicate the active DL BWP, from theconfigured DL BWP set, for DL receptions. In an example, if a bandwidthpart indicator field is configured in DCI format 0_1, the bandwidth partindicator field value may indicate the active UL BWP, from theconfigured UL BWP set, for UL transmissions.

In an example, for a primary cell, a wireless device may be provided bya higher layer parameter Default-DL-BWP a default DL BWP among theconfigured DL BWPs. If a wireless device is not provided a default DLBWP by the higher layer parameter Default-DL-BWP, the default DL BWP isthe initial active DL BWP. In an example, a wireless device may beprovided by higher layer parameter bwp-InactivityTimer, a timer valuefor the primary cell. If configured, the wireless device may incrementthe timer, if running, every interval of 1 millisecond for frequencyrange 1 or every 0.5 milliseconds for frequency range 2 if the wirelessdevice may not detect a DCI format 1_1 for paired spectrum operation orif the wireless device may not detect a DCI format 1_1 or DCI format 0_1for unpaired spectrum operation during the interval.

In an example, if a wireless device is configured for a secondary cellwith higher layer parameter Default-DL-BWP indicating a default DL BWPamong the configured DL BWPs and the wireless device is configured withhigher layer parameter bwp-InactivityTimer indicating a timer value, thewireless device procedures on the secondary cell may be same as on theprimary cell using the timer value for the secondary cell and thedefault DL BWP for the secondary cell.

In an example, if a wireless device is configured by higher layerparameter Active-BWP-DL-SCell a first active DL BWP and by higher layerparameter Active-BWP-UL-SCell a first active UL BWP on a secondary cellor carrier, the wireless device may use the indicated DL BWP and theindicated UL BWP on the secondary cell as the respective first active DLBWP and first active UL BWP on the secondary cell or carrier.

In an example, a set of PDCCH candidates for a wireless device tomonitor is defined in terms of PDCCH search space sets. A search spaceset comprises a CSS set or a USS set. A wireless device monitors PDCCHcandidates in one or more of the following search spaces sets: aType0-PDCCH CSS set configured by pdcch-ConfigSIB1 in MIB or bysearchSpaceSIB1 in PDCCH-ConfigCommon or by searchSpaceZero inPDCCH-ConfigCommon for a DCI format with CRC scrambled by a SI-RNTI onthe primary cell of the MCG, a Type0A-PDCCH CSS set configured bysearchSpaceOtherSystemInformation in PDCCH-ConfigCommon for a DCI formatwith CRC scrambled by a SI-RNTI on the primary cell of the MCG, aType1-PDCCH CSS set configured by ra-SearchSpace in PDCCH-ConfigCommonfor a DCI format with CRC scrambled by a RA-RNTI, a MsgB-RNTI, or aTC-RNTI on the primary cell, a Type2-PDCCH CSS set configured bypagingSearchSpace in PDCCH-ConfigCommon for a DCI format with CRCscrambled by a P-RNTI on the primary cell of the MCG, a Type3-PDCCH CSSset configured by SearchSpace in PDCCH-Config withsearchSpaceType=common for DCI formats with CRC scrambled by INT-RNTI,SFI-RNTI, TPC-PUSCH-RNTI, TPC-PUCCH-RNTI, TPC-SRS-RNTI, CI-RNTI, orPS-RNTI and, only for the primary cell, C-RNTI, MCS-C-RNTI, orCS-RNTI(s), and a USS set configured by SearchSpace in PDCCH-Config withsearchSpaceType=ue-Specific for DCI formats with CRC scrambled byC-RNTI, MCS-C-RNTI, SP-CSI-RNTI, CS-RNTI(s), SL-RNTI, SL-CS-RNTI, orSL-L-CS-RNTI.

In an example, a wireless device determines a PDCCH monitoring occasionon an active DL BWP based on one or more PDCCH configuration parameterscomprising: a PDCCH monitoring periodicity, a PDCCH monitoring offset,and a PDCCH monitoring pattern within a slot. For a search space set (SSs), the wireless device determines that a PDCCH monitoring occasion(s)exists in a slot with number n_(s,f) ^(μ) in a frame with number n_(f)if (n_(f)·N_(slot) ^(frame,μ)+n_(s,f) ^(μ)−o_(s)) mod k_(s)=0. N_(slot)^(frame,μ) is a number of slots in a frame when numerology p isconfigured. o_(s) is a slot offset indicated in the PDCCH configurationparameters. k_(s) is a PDCCH monitoring periodicity indicated in thePDCCH configuration parameters. The wireless device monitors PDCCHcandidates for the search space set for T_(s) consecutive slots,starting from slot n_(s,f) ^(μ), and does not monitor PDCCH candidatesfor search space set s for the next k_(s)−T_(s) consecutive slots. In anexample, a USS at CCE aggregation level L∈{1, 2, 4, 8, 16} is defined bya set of PDCCH candidates for CCE aggregation level L.

In an example, a wireless device decides, for a search space set sassociated with CORESET p, CCE indexes for aggregation level Lcorresponding to PDCCH candidate m_(s,n) _(CI) of the search space setin slot n_(s,f) ^(μ) for an active DL BWP of a serving cellcorresponding to carrier indicator field value n_(CI) as

${{L \cdot \{ {( {Y_{p,n_{s,f}^{\mu}} + \lfloor \frac{m_{s,n_{CI}} \cdot N_{{CCE},p}}{L \cdot M_{s,\max}^{(L)}} \rfloor + n_{CI}} ){mod}\lfloor {N_{{CCE},p}/L} \rfloor} \}} + i},$

where, Y_(p,n) _(s,f) _(μ) =0 for any CSS; Y_(p,n) _(s,f) _(μ)=(A_(p)·Y_(p,n) _(s,f) _(μ) ⁻¹) mod D for a USS, Y_(p,−1)=n_(RNTI)≠0,A_(p)=39827 for p mod 3=0, A_(p)=39829 for p mod 3=1, A_(p)=39839 for pmod 3=2, and D=65537; i=0, . . . , L−1; N_(CCE,p) is the number of CCEs,numbered from 0 to N_(CCE,p)−1, in CORESET p; n_(CI) is the carrierindicator field value if the wireless device is configured with acarrier indicator field by CrossCarrierSchedulingConfig for the servingcell on which PDCCH is monitored; otherwise, including for any CSS,n_(CI)=0; m_(s,n) _(CI) =0, . . . , M_(s,n) _(CI) ^((L))−1, whereM_(s,n) _(CI) ^((L)) is the number of PDCCH candidates the wirelessdevice is configured to monitor for aggregation level L of a searchspace set s for a serving cell corresponding to n_(CI); for any CSS,M_(s,max) ^((L))=M_(s,0) ^((L)); for a USS, M_(s,max) ^((L)) is themaximum of M_(s,n) _(CI) ^((L)) over all configured n_(CI) values for aCCE aggregation level L of search space set s; and the RNTI value usedfor n_(RNTI) is the C-RNTI.

In an example, a wireless device may monitor a set of PDCCH candidatesaccording to configuration parameters of a search space set comprising aplurality of search spaces (SSs). The wireless device may monitor a setof PDCCH candidates in one or more CORESETs for detecting one or moreDCIs. Monitoring may comprise decoding one or more PDCCH candidates ofthe set of the PDCCH candidates according to the monitored DCI formats.Monitoring may comprise decoding a DCI content of one or more PDCCHcandidates with possible (or configured) PDCCH locations, possible (orconfigured) PDCCH formats (e.g., number of CCEs, number of PDCCHcandidates in common SSs, and/or number of PDCCH candidates in theUE-specific SSs) and possible (or configured) DCI formats. The decodingmay be referred to as blind decoding. The possible DCI formats may bebased on example embodiments of FIG. 24 .

FIG. 24 shows examples of DCI formats which may be used by a basestation transmit control information to a wireless device or used by thewireless device for PDCCH monitoring. Different DCI formats may comprisedifferent DCI fields and/or have different DCI payload sizes. DifferentDCI formats may have different signaling purposes. In an example, DCIformat 0_0 may be used to schedule PUSCH in one cell. DCI format 0_1 maybe used to schedule one or multiple PUSCH in one cell or indicate CG-DFI(configured grant-Downlink Feedback Information) for configured grantPUSCH, etc. The DCI format(s) which the wireless device may monitor in aSS may be configured based on example embodiments with respect to FIG.27 , which will be explained later.

FIG. 25 shows an example of RRC configuration of a serving cell withdormancy configuration. In an example, a base station may transmit to awireless device, one or more configuration parameters for a dormancyoperation of a cell. In an example, the configuration parameters maycomprise dormancyGroupOutsideActiveTime comprising a bitmap for a numberof groups of configured SCells. The bitmap location may be immediatelyafter the Wake-up indication bit location (e.g., comprised in DCI format2_6). The bitmap size may be equal to the number of groups of configuredSCells where each bit of the bitmap corresponds to a group of configuredSCells from the number of groups of configured SCells. A ‘0’ value for abit of the bitmap indicates an active DL BWP, provided by dormantBWP-Id(e.g., as shown in FIG. 25 ), for the wireless device for each activatedSCell in the corresponding group of configured SCells. A ‘1’ value for abit of the bitmap may indicate an active DL BWP, provided byfirstOutsideActiveTimeBWP-Id, for the wireless device for each activatedSCell in the corresponding group of configured SCells, if a currentactive DL BWP is the dormant DL BWP, or may indicate a current active DLBWP, for the wireless device for each activated SCell in thecorresponding group of configured SCells, if the current active DL BWPis not the dormant DL BWP. The wireless device may set the active DL BWPto the indicated active DL BWP.

In an example, a wireless device may be provided (e.g., based on FIG.22A and/or FIG. 27 ) search space sets to monitor PDCCH for detection ofDCI format 2_6 in the active DL BWP of a PCell or of a SpCell. Thewireless device may detect DCI format 2_6. In an example, a DCI format2_6 may comprise a SCell dormancy indication field, wherein the SCelldormancy indication field is a bitmap with size equal to a number ofgroups of configured SCells, provided by dormancyGroupWithinActiveTime(e.g., as shown in FIG. 25 ), wherein each bit of the bitmap correspondsto a group of configured SCells from the number of groups of configuredSCells.

In an example, a wireless device may be configured with search spaces(or search space sets) to monitor PDCCH for detection of DCI format 0_1and DCI format 1_1, wherein one or both of DCI format 0_1 and DCI format1_1 include a SCell dormancy indication field. The wireless device mayset the active DL BWP to an indicated active DL BWP if the wirelessdevice detects a DCI format 0_1 or a DCI format 1_1 that does notinclude a carrier indicator field or detects a DCI format 0_1 or DCIformat 1_1 that includes a carrier indicator field with value equal to0. In an example, the indicated active DL BWP may be an active DL BWP,provided by dormantBWP-Id, for the wireless device for each activatedSCell in a group of configured SCells, if a bit, corresponding to thegroup, of the SCell dormancy indication bitmap is set to a ‘0’ value. Inan example, if the bit is set to a ‘1’ value, the indicated active DLBWP may be an active DL BWP, provided by firstWithinActiveTimeBWP-Id,for the wireless device for each activated SCell in the correspondinggroup of configured SCells, if a current active DL BWP is the dormant DLBWP, or a current active DL BWP, for the wireless device for eachactivated SCell in the corresponding group of configured SCells, if thecurrent active DL BWP is not the dormant DL BWP.

In an example, a wireless device may determine a DCI (e.g., DCI format1_1) as indicating SCell dormancy (e.g., not scheduling a PDSCHreception or indicating a SPS PDSCH release) based on at least one ofthe following conditions: the wireless device being provided with searchspace sets to monitor PDCCH for detection of the DCI, the CRC of the DCIbeing scrambled by a C-RNTI or a MCS-C-RNTI, a one-shot HARQ-ACK requestfield not being present or has a ‘0’ value, the DCI detected on a PCellnot including a carrier indicator field or including a carrier indicatorfield with value equal to 0, resourceAllocation=resourceAllocationType0and all bits of the frequency domain resource assignment field in theDCI being equal to 0, resourceAllocation=resourceAllocationType1 and allbits of the frequency domain resource assignment field in the DCI beingequal to 1, and/or resourceAllocation=dynamicSwitch and all bits of thefrequency domain resource assignment field in DCI format 1_1 being equalto 0 or 1. In an example, in response to determining the DCI asindicating the SCell dormancy, the wireless device may consider, fortransport block 1, a sequence of fields of MCS, NDI, RV and HARQ processnumber, antenna port(s), DMRS sequence initialization as providing abitmap to each configured SCell, in an ascending order of SCell index. A‘0’ value for a bit of the bitmap may indicate an active DL BWP,provided by dormantBWP-Id, for the wireless device for a correspondingactivated SCell. A ‘1’ value for a bit of the bitmap may indicate anactive DL BWP, provided by firstWithinActiveTimeBWP-Id, for the wirelessdevice for a corresponding activated SCell, if a current active DL BWPis the dormant DL BWP or a current active DL BWP, for the wirelessdevice for a corresponding activated SCell, if the current active DL BWPis not the dormant DL BWP. The wireless device may set the active DL BWPto the indicated active DL BWP.

In an example, if an active DL BWP provided by dormantBWP-Id for awireless device on an activated SCell is not a default DL BWP for thewireless device on the activated SCell, the BWP inactivity timer is notused for transitioning from the active DL BWP provided by dormantBWP-Idto the default DL BWP on the activated SCell.

In an example, a wireless device may provide HARQ-ACK information inresponse to a detection of a DCI format 1_1 indicating SCell dormancyafter N symbols from the last symbol of a PDCCH providing the DCI format1_1. If processingType2Enabled of PDSCH-ServingCellConfig is set toenable for the serving cell with the PDCCH providing the DCI format 1_1,N=7 for μ=0, N=7.5 for μ=1, and N=15 for μ=2; otherwise, N=14 for μ=0,N=16 for μ=1, N=27 for μ=2, and N=31 for μ=3, where μ is the smallestSCS configuration between the SCS configuration of the PDCCH providingthe DCI format 1_1 and the SCS configuration of a PUCCH with theHARQ-ACK information in response to the detection of the DCI format 1_1.

FIG. 26 shows an example of RRC configuration parameters (e.g.,BWP-DownlinkDedicated IE) of a downlink BWP of a serving cell. A basestation may transmit to a wireless device (or a plurality of wirelessdevices) one or more configuration parameters of a downlink BWP (e.g.,initial downlink BWP) of a serving cell. As shown in FIG. 26 , the oneor more configuration parameters of the downlink BWP may comprise: oneor more parameters for PDCCH of the downlink BWP (e.g., in pdcch-ConfigIE), and one or more other parameters. A pdcch-Config IE may compriseparameters of one or more control resource sets (CORESETs) which can beused in any common or UE-specific search spaces for the bandwidth part.The one or more parameters of the PDCCH may indicate a plurality ofsearch spaces for the bandwidth part, each search space being associatedwith a search space ID. The one or more parameters of the PDCCH maycomprise a search space switch configuration parameter (e.g.,searchSpaceSwitchConfig-r16 IE) indicating one or more cell groups forsearch space switching. When a bit, of a search space switchingindication bitmap of a DCI (e.g., DCI format 2_0), indicates a firstvalue, a wireless device may switch to a first search space group forall cells in a cell group corresponding to the bit. When a bit, of asearch space switching indication bitmap of a DCI (e.g., DCI format2_0), indicates a second value, a wireless device may switch to a secondsearch space group for all cells in a cell group corresponding to thebit.

As shown in FIG. 26 , a CORESET may be associated with a CORESET index(e.g., ControlResourceSetId). The CORESET index with a value of 0 mayidentify a common CORESET configured in MIB and inServingCellConfigCommon (controlResourceSetZero) and may not be used inthe ControlResourceSet IE. The CORESET index with other values mayidentify CORESETs configured by dedicated signaling or in SIB1. ThecontrolResourceSetId is unique among the BWPs of a serving cell. ACORESET may be associated with coresetPoolIndex indicating an index of aCORESET pool for the CORESET. A CORESET may be associated with a timeduration parameter (e.g., duration) indicating contiguous time durationof the CORESET in number of symbols. In an example, as shown in FIG. 26, configuration parameters of a CORESET may comprise at least one of:frequency resource indication (e.g., frequencyDomainResources), aCCE-REG mapping type indicator (e.g., cce-REG-MappingType), a pluralityof TCI states, an indicator indicating whether a TCI is present in aDCI, and the like. The frequency resource indication, comprising anumber of bits (e.g., 45 bits), indicates frequency domain resources,each bit of the indication corresponding to a group of 6 RBs, withgrouping starting from the first RB group in a BWP of a cell (e.g.,SpCell, SCell). The first (left-most/most significant) bit correspondsto the first RB group in the BWP, and so on. A bit that is set to 1indicates that an RB group, corresponding to the bit, belongs to thefrequency domain resource of this CORESET. Bits corresponding to a groupof RBs not fully contained in the BWP within which the CORESET isconfigured are set to zero.

In an example, a base station may transmit to a wireless device one ormore RRC messages comprising PDCCH configuration parameters (e.g.,PDCCH-ServingCellConfig IE as shown in FIG. 26 ) applicable for alldownlink BWPs of a cell. In an example, the PDCCH configurationparameters may comprise a timer value (e.g., an integer in units ofsymbol/slot, or in units of ms) for a search space switch timer (e.g.,searchSpaceSwitchTimerIE). The search space switch timer and the timevalue may be used for a search space switching operation which will bedescribed in FIG. 28B.

FIG. 27 shows an example of configuration of a search space (e.g.,SearchSpace IE) of a BWP. In an example, one or more search spaceconfiguration parameters of a search space may comprise at least one of:a search space ID (searchSpaceId), a control resource set ID (controlResourceSetId), a monitoring slot periodicity and offset parameter(monitoringSlotPeriodicityAndOffset), a search space time duration value(duration), a monitoring symbol indication(monitoringSymbolsWithinSlot), a number of candidates for an aggregationlevel (nrofCandidates), and/or a SS type indicating a common SS type ora UE-specific SS type (searchSpaceType). The monitoring slot periodicityand offset parameter may indicate slots (e.g., in a radio frame) andslot offset (e.g., related to a starting of a radio frame) for PDCCHmonitoring. The monitoring symbol indication may indicate on whichsymbol(s) of a slot a wireless device may monitor PDCCH on the SS. Thecontrol resource set ID may identify a control resource set on which aSS may be located.

As shown in FIG. 27 , the one or more search space configurationparameters of a search space may comprise a search space group list(e.g., searchSpaceGroupIdList), indicating one or more search spacegroups the search space may belong to, for search space switchingoperation. A search space switching operation may be based on exampleembodiment of FIG. 28A and/or FIG. 28B.

FIG. 28A shows an example of DCI format 2_0 comprising one or moresearch space set group (or SSSG) switching indications (or Search spaceset group switching flags). In an example, a DCI format 2_0 may compriseone or more slot format indicator (e.g., slot format indicator 1, slotformat indicator 2, . . . slot format indicator N), one or moreavailable RB set indicators, one or more COT duration indications, oneor more SSS group switching flags. In an example, each of the one ormore SSS group switching flags may correspond to a respective cell groupof a plurality of cell groups. The plurality of cell groups may beimplemented based on example embodiments described above with respect toFIG. 26 . Each cell group of the plurality of cell groups may compriseone or more cells. A SSS group switching flag, of the one or more SSSgroup switching flags, corresponding to a cell group, may indicate, whensetting to a first value, switching from a first SSS group to a secondSSS group for each cell of the cell group. The SSS group switching flagmay indicate, when setting to a second value, switching from the secondSSS group to the first SSS group for each cell of the cell group. In anexample, a plurality of SSS groups, comprising the first SSS group andthe second SSS group, may be configured based on example embodimentsdescribed above with respect to FIG. 27 . The wireless device mayperform SSS group switching based on example embodiment of FIG. 28B.

FIG. 28B shows an example of SSS group switching based on a DCI (e.g.,DCI format 2_0, or other DCI formats described in FIG. 24 ). In anexample, a wireless device may be provided a group index for a searchspace set (e.g., a Type3-PDCCH CSS set, a USS set, or any other type ofsearch space set) by searchSpaceGroupIdList (e.g., based on exampleembodiment of FIG. 27 ) for PDCCH monitoring on a serving cell.

In an example, the wireless device may not be providedsearchSpaceGroupIdList for a search space set. The embodiments of FIG.28B may not be applicable for PDCCH monitoring on the search space ifthe search space set is not configured with searchSpaceGroupIdList.Based on not applying the embodiments of FIG. 28B, the wireless devicemay monitor the search space set on a BWP, without switching away fromthe search space set for PDCCH monitoring.

In an example, if a wireless device is provided cellGroupsForSwitchList(e.g., based on example embodiments shown in FIG. 26 ), indicating oneor more groups of serving cells, the embodiments of FIG. 28B may applyto all serving cells within each group. If the wireless device is notprovided cellGroupsForSwitchList, the embodiments of FIG. 28B may applyonly to a serving cell for which the wireless device is providedsearchSpaceGroupIdList.

In an example, if a wireless device is provided searchSpaceGroupIdList,the wireless device may reset PDCCH monitoring according to search spacesets with group index 0, if provided by searchSpaceGroupIdList.

In an example, a wireless device may be provided bysearchSpaceSwitchDelay (e.g., as shown in FIG. 26 ) with a number ofsymbols P_(switch) based on UE processing capability (e.g., UEprocessing capability 1, UE processing capability 2, etc.) and SCSconfiguration μ. UE processing capability 1 for SCS configuration μ mayapply unless the wireless device indicates support for UE processingcapability 2. In an example, P_(switch)=25 for UE capability 1 and μ=0,P_(switch)=25 for UE capability 1 and μ=1, P_(switch)=25 for UEcapability 1 and μ=2, P_(switch)=10 for UE capability 2 and μ=0,P_(switch)=12 for UE capability 2 and μ=1, and P_(switch)=22 for UEcapability 2 and μ=2, etc.

In an example, a wireless device may be provided, bysearchSpaceSwitchTimer (in units of slots, e.g., as shown in FIG. 26 ),with a timer value for a serving cell that the wireless device isprovided searchSpaceGroupIdList or, if provided, for a set of servingcells provided by cellGroupsForSwitchList. The wireless device maydecrement the timer value by one after each slot based on a referenceSCS configuration that is a smallest SCS configuration μ among allconfigured DL BWPs in the serving cell, or in the set of serving cells.The wireless device may maintain the reference SCS configuration duringthe timer decrement procedure.

In an example, searchSpaceSwitchTimer may be defined as a value in unitof slots for monitoring PDCCH in the active DL BWP of the serving cellbefore moving to a default search space group (e.g., search space group0). For 15 kHz SCS, a valid timer value may be one of {1, . . . , 20}.For 30 kHz SCS, a valid timer value may be one of {1, . . . , 40}. For60 kHz SCS, a valid timer value may be one of {1, . . . , 80}. In anexample, the base station may configure a same timer value for allserving cells in the same CellGroupForSwitch.

As shown in FIG. 28B, the wireless device may monitor PDCCH on a firstSSS group (e.g., 1^(st) SSS group or a SSS with group index 0) based onconfiguration of SSS groups of a BWP of a cell. The wireless device maybe provided by SearchSpaceSwitchTrigger with a location of a searchspace set group switching flag field for a serving cell in a DCI format2_0. The SearchSpaceSwitchTrigger may be configured based on exampleembodiments of FIG. 27 . The wireless device may receive a DCI (e.g.,1^(st) DCI in FIG. 28B with DCI format 2_0). The DCI may indicate a SSSgroup switching for the cell, e.g., when a value of the SSS groupswitching flag field in the DCI format 2_0 is 1. In response toreceiving the DCI, the wireless device may start monitoring PDCCHaccording to a second SSS group (e.g., 2^(nd) SSS group or a SSS withgroup index 1) and stops monitoring PDCCH on the first SSS group (or theSSS with group index 0 for the serving cell. The wireless device maystart monitoring PDCCH on the second SSS group (e.g., 2^(nd) SSS groupor a SSS with group index 1) and stops monitoring PDCCH on the first SSSgroup at a first slot that is at least P_(switch) symbols after a lastsymbol of the PDCCH with the DCI format 2_0. Based on receiving the DCI,the wireless device may set a timer value of the search space switchingtimer to the value provided by searchSpaceSwitchTimer.

In an example, the wireless device may monitor PDCCH on a second SSSgroup (e.g., 2^(nd) SSS group or a SSS with group index 1) based onconfiguration of SSS groups of a BWP of a cell. The wireless device maybe provided by SearchSpaceSwitchTrigger a location of a search space setgroup switching flag field for a serving cell in a DCI format 2_0. Thewireless device may receive a DCI. The DCI may indicate a SSS groupswitching for the cell, e.g., when a value of the search space set groupswitching flag field in the DCI format 2_0 is 0, the wireless device maystart monitoring PDCCH according to search space sets with group index 0and stop monitoring PDCCH according to search space sets with groupindex 1 for the serving cell. The wireless device may start monitoringthe PDCCH according to search space set with group index 0 and stopmonitoring PDCCH according to search space sets with group 1 at a firstslot that is at least P_(switch) symbols after the last symbol of thePDCCH with the DCI format 2_0.

In an example, if the wireless device monitors PDCCH for a serving cellaccording to a first SSS group (e.g., search space sets with group index1), the wireless device may start monitoring PDCCH for the serving cellaccording to a second SSS group (e.g., search space sets with groupindex 0), and stop monitoring PDCCH according to the first SSS group,for the serving cell at the beginning of the first slot that is at leastP_(switch) symbols after a slot where the timer expires or after a lastsymbol of a remaining channel occupancy duration for the serving cellthat is indicated by DCI format 2_0.

In an example, a wireless device may not be providedSearchSpaceSwitchTrigger for a serving cell, e.g.,SearchSpaceSwitchTrigger being absent in configuration parameters ofSlotFormatIndicator, wherein the SlotFormatIndicator is configured formonitoring a Group-Common-PDCCH for Slot-Format-Indicators (SFI). Inresponse to the SearchSpaceSwitchTrigger not being provided, the DCIformat 2_0 may not comprise a SSS group switching flag field. When theSearchSpaceSwitchTrigger is not provided, if the wireless device detectsa DCI format by monitoring PDCCH according to a first SSS group (e.g., asearch space set with group index 0), the wireless device may startmonitoring PDCCH according to a second SSS group (e.g., a search spacesets with group index 1) and stop monitoring PDCCH according to thefirst SSS group, for the serving cell. The wireless device may startmonitoring PDCCH according to the second SSS group and stop monitoringPDCCH according to the first SSS group at a first slot that is at leastP_(switch) symbols after the last symbol of the PDCCH with the DCIformat. The wireless device may set (or restart) the timer value to thevalue provided by searchSpaceSwitchTimer if the wireless device detectsa DCI format by monitoring PDCCH in any search space set.

In an example, a wireless device may not be providedSearchSpaceSwitchTrigger for a serving cell. When theSearchSpaceSwitchTrigger is not provided, if the wireless devicemonitors PDCCH for a serving cell according to a first SSS group (e.g.,a search space sets with group index 1), the wireless device may startmonitoring PDCCH for the serving cell according to a second SSS group(e.g., a search space sets with group index 0), and stop monitoringPDCCH according to the first SSS group, for the serving cell at thebeginning of the first slot that is at least P_(switch) symbols after aslot where the timer expires or, if the wireless device is provided asearch space set to monitor PDCCH for detecting a DCI format 2_0, aftera last symbol of a remaining channel occupancy duration for the servingcell that is indicated by DCI format 2_0.

In an example, a wireless device may determine a slot and a symbol in aslot to start or stop PDCCH monitoring according to search space setsfor a serving cell that the wireless device is providedsearchSpaceGroupIdList or, if cellGroupsForSwitchList is provided, for aset of serving cells, based on the smallest SCS configuration μ amongall configured DL BWPs in the serving cell or in the set of servingcells and, if any, in the serving cell where the wireless devicereceives a PDCCH and detects a corresponding DCI format 2_0 triggeringthe start or stop of PDCCH monitoring according to search space sets.

In an example, a wireless device may perform PDCCH skipping mechanismfor power saving operation. FIG. 29 shows an example of PDCCH skippingbased power saving operation.

In an example, a base station may transmit to a wireless device one ormore RRC messages comprising configuration parameters of PDCCH for a BWPof a cell (e.g., based on example embodiments described above withrespect to FIG. 26 and/or FIG. 27 ). Based on the configurationparameters of PDCCH, the wireless device may monitor PDCCH on the BWP.The BWP may a downlink BWP which is in active state. The wireless devicemay activate the BWP based on example embodiments described above withrespect to FIG. 23 .

As shown in FIG. 29 , the wireless device may receive a first DCI (e.g.,1^(st) DCI) indicating skipping PDCCH with a time window. A time valuefor the time window may be indicated by the first DCI or configured bythe one or more RRC messages. In response to receiving the first DCI,the wireless device may stop monitoring PDCCH on the BWP. Stoppingmonitoring PDCCH on the BWP may comprise stopping monitoring PDCCH onone or more SSS groups configured on the BWP. The wireless devicemaintain an active state of the BWP. The first DCI may not indicate anactive BWP switching. In an example, during the time window (or when atimer associated with the time window is running), the base station maynot transmit PDCCH to the wireless device.

As shown in FIG. 29 , when the time window expires, the wireless devicemay resume PDCCH monitoring on the BWP. Based on resuming PDCCHmonitoring the wireless device may receive a second DCI (e.g., 2^(nd)DCI) scheduling TB via s PDSCH. The wireless device may receive the TBvia the PDSCH scheduled by the second DCI. In an example, in response tothe time window expiring, the base station may transmit the second DCIto the wireless device.

In existing technologies, a wireless device may receive a first DCIcomprising a SSG indication indicating that the wireless device switchesPDCCH monitoring from a first SSG to a second SSG on a BWP, e.g., basedon example embodiments described above with respect to FIG. 28A and/orFIG. 28B. The wireless device may receive a second DCI comprising aPDCCH skipping indication indicating that the wireless device skipsPDCCH monitoring on the BWP for a time duration, e.g., based on exampleembodiments described above with respect to FIG. 29 . Based onimplementing existing technologies, in response to receiving the secondDCI after receiving the first DCI, there exists ambiguity as to how thewireless device should behave regarding the SSG switching operation andthe PDCCH skipping operation. Most likely, the time windows for the SSGswitching operation and the PDCCH skipping operation do not align.

In an example, by implementing existing technologies, the wirelessdevice may have difficulty in determining: whether the wireless deviceshould stop or maintain PDCCH monitoring on the SSG indicated by thefirst DCI; whether the wireless device should stop or keep running afirst time window associated with the SSG; when the wireless deviceshould start monitoring a second SSG; when the wireless device shouldstart a second time window associated with the second SSG, etc.

More specifically, by implementing existing technologies, when the firsttime window associated with the SSG (e.g., a search space switchingtimer) expires before a time duration for PDCCH skipping, the wirelessdevice does not know whether to switch from the SSG to a default SSG(e.g., SSG with group index 0) immediately after the expiry of the firsttime window, or delay the SSG switching until the end of the timeduration on which the wireless device is in PDCCH skipping. Theambiguity in the wireless device's behavior may result in misalignmentbetween the wireless device and the base station regarding the PDCCHskipping operation and the SSG switching operation.

Therefore, there is a need to design and designate the wireless devicebehavior to align the wireless device with the base station when a PDCCHskipping indication is received after the SSG switching operation.Example embodiments further described below may reduce power consumptionof a wireless device and/or reduce signaling transmission latency.

FIG. 30 shows an example embodiment of power saving operation with PDCCHskipping and SSS group switching. In an example, a base station maytransmit to a wireless device one or more RRC messages comprisingconfiguration parameters of a plurality of search space groups (SSGs) ona BWP of a cell. The configuration parameters may be implemented basedon example embodiments described above with respect to FIG. 27 . An SSG,of the plurality of SSGs, identified by a SSG index, may comprise one ormore search spaces. A search space comprised in a SSG may comprise atleast one of: a Type0-PDCCH CSS, a Type0A-PDCCH CSS, a Type1-PDCCH CSS,a Type2-PDCCH CSS, a Type3-PDCCH CSS and/or a UE-specific search space(USS).

In an example, an SSG may not comprise any search spaces on a BWP. TheSSG, not comprising any search spaces, may be referred to as a dormant(empty, non-active, virtual, etc.) SSG in this specification. A dormantSSG may be configured on a non-dormant BWP. A dormant SSG may not beconfigured on a dormant BWP. A dormant BWP or a non-dormant BWP may beimplemented based on example embodiments described above with respect toFIG. 23 and/or FIG. 25 . An SSG comprising at least one search space maybe referred to as a non-dormant SSG. The wireless device may switch to adormant SSG or a non-dormant SSG, based on a RRC message, a MAC CE aDCI, and/or one or more timers.

As shown in FIG. 30 , the wireless device may monitor PDCCH according to(or on) a first SSG, of the plurality of SSGs, on the BWP. The first SSGmay be a default SSG configured by the one or more RRC messages. Thefirst SSG may be a SSG with group index equal to 0. The wireless devicemay receive, during monitoring the PDCCH on the first SSG, a first DCI(e.g., 1^(st) DCI) comprising a SSG switching indication indicatingswitching from the first SSG to a second SSG of the plurality of SSGs onthe BWP. The first DCI may comprise a SSG index indicating the secondSSG to which the wireless device switches PDCCH monitoring from thefirst SSG. The first DCI may be with a DCI format based on exampleembodiments described above with respect to FIG. 24 .

In an example, when configured with DRX operation, the wireless devicemay receive the first DCI in a DRX on duration of a DRX cycle.

As shown in FIG. 30 , in response to receiving the SSG switchingindication in the first DCI, the wireless device may switch PDCCHmonitoring from the first SSG to the second SSG on the BWP. The wirelessdevice may start a first time window (or a first timer) based on a firsttimer value associated with the first time window. The first timer valuemay be indicated by the first DCI. The first timer value may beindicated by the one or more RRC messages. The first timer value may beper SSG configured by the one or more RRC messages. A first SSG may beconfigured with a separate and/or independent timer value from a secondSSG on the BWP. The first timer value may be per BWP configured by theone or more RRC messages. Based on the per BWP configured first timervalue, the wireless device may apply the same timer value for theplurality of SSGs comprising the first SSG and the second SSG.

In an example embodiment, the wireless device may restart the first timewindow in response to receiving a DCI (e.g., a downlink scheduling DCI,an uplink grant DCI, etc., via one or more SS of the second SSG, notshown in FIG. 30 ), after receiving the first DCI indicating the SSGswitching.

In an example, the wireless device may decrement, the first timerassociated with the first time window, in a slot during which thewireless device does not receive a DCI.

As shown in FIG. 30 , the wireless device may receive a second DCI(e.g., 2^(nd) DCI) comprising a PDCCH skipping indication indicatingskipping PDCCH monitoring on the BWP. In response to receiving the PDCCHskipping indication, the wireless device may stop monitor the second SSG(e.g., and the first SSG) and start a second time window (or a secondtimer) based on a second timer value.

In an example embodiment, the second timer value may be indicated by theone or more RRC message and/or the second DCI. The one or more RRCmessages may indicate a plurality of second timer values (e.g., in unitof slot) for the PDCCH skipping. The second DCI may indicate one of theplurality of second timer values configured by the one or more RRCmessages. A time value, indicated by the DCI and/or the one or more RRCmessages, for the PDCCH skipping, may be implemented based on exampleembodiments of FIG. 36 which will be described later.

As shown in FIG. 30 , in response to receiving the PDCCH skippingindication, the wireless device may stop the first time windowassociated with the second SSG on the BWP. Stopping the first timewindow, in response to receiving the PDCCH skipping indication, mayavoid unnecessary SSG switching during the second time window in whichthe wireless device skips PDCCH monitoring on the BWP. Otherwise,keeping the first time window running, during the PDCCH skipping, mayresult in switching to a second SSG when the first time window expires,while the wireless device is not monitoring the PDCCH due to the PDCCHskipping indication. Example embodiment may improve power consumption ofa wireless device and/or align with the base station regarding which ofthe plurality of SSGs the wireless device will monitor after the PDCCHskipping for a time window.

As shown in FIG. 30 , the wireless device may skip PDCCH monitoring (onthe first SSG and/or the second SSG, or any SSG of the plurality ofSSGs) on the BWP based on receiving the PDCCH skipping indication in thesecond DCI, during the second time window, or when a timer associatedwith the second time window is running.

As shown in FIG. 30 , the second time window may expire. In response tothe second time window expiring, the wireless device may resume (orrestart) PDCCH monitoring on the BWP. The wireless device may resumePDCCH monitoring on the second SSG (e.g., may not switch to the firstSSG). The wireless device may, in response to resuming PDCCH monitoringon the second SSG (e.g., not switching to the first SSG), restart thefirst time window associated with the second SSG. Otherwise, if notrestarting the first time window associated with the second SSG, thewireless device may stay on the second SSG for a long time notcontrolled by the first time window, which may increase powerconsumption. The wireless device may restart the first time window fromthe initial time value (e.g., indicated by the first DCI and/or the RRCmessage). The wireless device may restart the first time window from avalue, different form the initial time value, which is reached when thewireless device stops the first time value after the wireless devicereceives the second DCI.

As shown in FIG. 30 , when the wireless device monitors the second SSGduring the first time window (e.g., after restarting the first timewindow), the wireless device may receive a third DCI (e.g., 3^(rd) DCI)scheduling a TB via a PDSCH (or a PUSCH) via the second SSG. Thewireless device may receive the TB via the PDSCH (or transmit the TB viathe PUSCH). The wireless device may restart the first time window inresponse to receiving the second DCI.

In an example, in response to the first time window expiring, thewireless device may switch to the first SSG for PDCCH monitoring on theBWP of the cell.

In an example embodiment, when the wireless device is configured withDRX operation (e.g., based on example embodiments described above withrespect to FIG. 22A and/or FIG. 22B), one or more example embodiments ofFIG. 30 may be applied in a time duration when the DRX operation is inactive time (e.g., when a DRX on duration timer is running, a DRXinactivity timer is running, DRX retransmission timers are running, a SRis sent on PUCCH and is pending, or a PDCCH indicating a newtransmission addressed to the C-RNTI of the MAC entity has not beenreceived after successful reception of a RAR for the Random AccessPreamble not selected by the MAC entity among the contention-basedRandom Access Preamble). Appling the one or more embodiments of FIG. 30in the DRX active time may comprise monitoring PDCCH, receiving the oneor more DCIs (1^(st) DCI, 2^(nd) DCI, 3^(rd) DCI, etc.) in the DRXactive time.

Based on example embodiments, the wireless device may stop a time window(e.g., if running) associated with a SSG of a BWP in response toreceiving a DCI comprising a PDCCH skipping indication indicatingstopping PDCCH monitoring on the BWP. The DCI may comprise a time valueindicating a time period, after the wireless device receives the DCI,during which the wireless device may stop (or skip) PDCCH monitoring onthe BWP. Example embodiments may avoid unnecessary SSG switching duringa time period when the wireless device does not monitor PDCCH on theBWP. Example embodiment may improve power consumption of a wirelessdevice and/or align with the base station regarding which of theplurality of SSGs the wireless device will monitor after the PDCCHskipping for a time window.

FIG. 31 shows an example embodiment of power saving operation with PDCCHskipping and SSG switching. In an example, a base station may transmitto a wireless device one or more RRC messages comprising configurationparameters of a plurality of search space groups (SSGs) on a BWP of acell. The configuration parameters may be implemented based on exampleembodiments described above with respect to FIG. 27 and/or FIG. 30 .

As shown in FIG. 31 , the wireless device may monitor PDCCH according to(or on) a first SSG, of the plurality of SSGs, on the BWP. The first SSGmay be a default SSG configured by the one or more RRC messages. Thefirst SSG may be a SSG with group index equal to 0. The wireless devicemay receive, during monitoring the PDCCH on the first SSG, a first DCI(e.g., 1^(st) DCI) comprising a SSG switching indication indicatingswitching from the first SSG to a second SSG of the plurality of SSGs onthe BWP. The first DCI may comprise a SSG index indicating the secondSSG to which the wireless device switches PDCCH monitoring from thefirst SSG. The first DCI may be with a DCI format based on exampleembodiments described above with respect to FIG. 24 .

As shown in FIG. 31 , in response to receiving the SSG switchingindication in the first DCI, the wireless device may switch PDCCHmonitoring from the first SSG to the second SSG on the BWP. The wirelessdevice may start a first time window (or a first timer) based on a firsttimer value associated with the first time window. In an exampleembodiment, the first timer value may be indicated by the first DCIand/or the one or more RRC messages, e.g., based on example embodimentsdescribed above with respect to FIG. 30 .

In an example, the wireless device may decrement, the first timerassociated with the first time window, in a slot during which thewireless device does not receive a DCI.

As shown in FIG. 31 , the wireless device may receive a second DCI(e.g., 2^(nd) DCI) comprising a PDCCH skipping indication indicatingskipping PDCCH monitoring on the BWP. In response to receiving the PDCCHskipping indication, the wireless device may stop monitor the second SSG(e.g., and the first SSG) and start a second time window (or a secondtimer) based on a second timer value (e.g., based on example embodimentsdescribed above with respect to FIG. 30 ).

As shown in FIG. 31 , in response to receiving the PDCCH skippingindication, the wireless device may keep running the first time windowassociated with the second SSG on the BWP. Keeping running the firsttime window, in response to receiving the PDCCH skipping indication, maysimplify implementation cost of the wireless device for management ofthe first time window and the second time window.

As shown in FIG. 31 , the wireless device may skip PDCCH monitoring (onthe first SSG and/or the second SSG, or any SSG of the plurality ofSSGs) on the BWP based on receiving the PDCCH skipping indication in thesecond DCI, during the second time window, or when a timer associatedwith the second time window is running. The wireless device may keep thefirst time window and the second time window running simultaneously.

In an example, a wireless device may determine whether the first timewindow expires earlier than the second time window, when both the firsttime window and the second time window are running. As shown in FIG. 31, the first time window may expire before the second time window does.In response to the first time window expiring earlier than the secondtime window, the wireless device may switch PDCCH monitoring from thesecond SSG to the first SSG on the BWP. The wireless device may disable(or stop) the second time window (if running, or not expiring), inresponse to switching PDCCH monitoring to the first SSG on the BWP. Inresponse to disabling the second time window, the wireless device maymonitor the first SSG on the BWP. The wireless device, during monitoringthe first SSG, may receive a third DCI scheduling a TB via a PDSCH (or aPUSCH) via the first SSG. The wireless device may receive the TB via thePDSCH (or transmit the TB via the PUSCH). The wireless device mayrestart the first time window in response to receiving the third DCI. Inan example, in response to the first time window expiring, the wirelessdevice may switch to the second SSG for PDCCH monitoring on the BWP ofthe cell.

In an example embodiment, the first time window may expire before thesecond time window does. In response to the first time window expiringearlier than the second time window, the wireless device may switch fromthe second SSG to the first SSG on the BWP and/or stop the first timewindow. The wireless device may keep running the second time window. Inresponse to keeping running the second time window (or the second timewindow not expiring), the wireless device may not start monitoring thefirst SSG on the BWP, after the wireless device switches to the firstSSG. The wireless device may start monitoring the first SSG on the BWP,in response to the second time window expiring.

In an example embodiment, the second time window may expire before thefirst time window does, when both the first time window and the secondtime window are running simultaneously. In response to the second timewindow expiring earlier than the first time window, the wireless devicemay resume PDCCH monitoring (e.g., without switching to the first SSG)on the second SSG on the BWP. The wireless device, during monitoring thesecond SSG, may receive a fourth DCI scheduling a TB via a PDSCH (or aPUSCH) via the second SSG. The wireless device may receive the TB viathe PDSCH (or transmit the TB via the PUSCH). The wireless device mayrestart the first time window in response to receiving the fourth DCI.In an example, in response to the first time window expiring, thewireless device may switch from the second SSG to the first SSG forPDCCH monitoring on the BWP of the cell.

In an example embodiment, when the wireless device is configured withDRX operation (e.g., based on example embodiments described above withrespect to FIG. 22A and/or FIG. 22B), one or more example embodiments ofFIG. 31 may be applied in a time duration when the DRX operation is inactive time (e.g., a DRX on duration timer is running, a DRX inactivitytimer is running, DRX retransmission timers are running, a SR is sent onPUCCH and is pending, or a PDCCH indicating a new transmission addressedto the C-RNTI of the MAC entity has not been received after successfulreception of a RAR for the Random Access Preamble not selected by theMAC entity among the contention-based Random Access Preamble). Applingthe one or more embodiments of FIG. 31 in the DRX active time maycomprise monitoring PDCCH, receiving the one or more DCIs (1^(st) DCI,2^(nd) DCI, 3^(rd) DCI, etc.) in the DRX active time.

Based on example embodiments of FIG. 31 , a wireless device may maintaina first time window for SSG switching and a second time window for PDCCHskipping running simultaneously. The wireless device may switch from afirst SSG to a second SSG on a BWP in response to the first time windowexpiring before the second time window expires.

In an example embodiment, the wireless device, in response to switchingto the second SSG, may disable (or stop) the second time window (forPDCCH skipping on the BWP) if the second time window is running. Inresponse to disabling (or stopping) the second time window, the wirelessdevice may start monitoring the second SSG on the BWP and start thefirst time window associated with the second SSG. Example embodimentsmay reduce data transmission latency.

In an example embodiment, the wireless device, may keep running thesecond time window in response to switching to the second SSG. After thewireless device switches to the second SSG, the wireless device may notstart the first time window associated with the second SSG and/or maynot monitor the second SSG on the BWP when the second time window isrunning. The wireless device may start the first time window associatedwith the second SSG in response to the second time window expires. Thewireless device may start monitoring the second SSG in response tostarting the first time window. Example embodiments may reduce powerconsumption of the wireless device.

FIG. 32 shows an example embodiment of power saving operation with SSGswitching and PDCCH skipping, based on example embodiments describedabove with respect to FIG. 30 and/or FIG. 31 .

In an example, a wireless device may be configured with a plurality ofSSGs (SSG-0, SSG-1, SSG-2 and etc.) in a BWP, e.g., based on exampleembodiments described above with respect to FIG. 30 and/or FIG. 31 . Thewireless device may monitor PDCCH on SSG-1, when a SSG switching timerassociated with SSG-1 is running. The wireless device may receive, at afirst slot (T0), a DCI (1^(st) DCI) indicating PDCCH skipping for a timeduration (e.g., a number of slots) on the BWP, when the SSG switchingtimer is running, e.g., based on example embodiments described abovewith respect to FIG. 30 and/or FIG. 31 . In response to receiving theDCI indicating the PDCCH skipping for the time duration, the wirelessdevice may skip PDCCH monitoring on SSG-1 in the time duration, e.g.,starting from the first slot (T0) to a second slot (T2). The time gapbetween T0 and T2 is indicated by the time duration. Between T0 and T2,the SSG switching timer associated with SSG-1 may expire (e.g., in athird slot, T1, when no DCI is received before the expiry of the SSGswitching timer associated with SSG-1). In response to the SSG switchingtimer expiring in a slot (e.g., T1) within the time duration between T0and T2, the wireless device may delay the PDCCH monitoring on SSG-0until (or after) the second slot T2 when the wireless device completesthe PDCCH skipping for the time duration. In response to the SSGswitching timer expiring in a slot (e.g., T1) within the time durationbetween T0 and T2, the wireless device does not monitor SSG-0 between T1and T2. When (or after) the wireless device completes the PDCCH skippingfor the time duration, e.g., at T2, the wireless device may start tomonitor SSG-0 of the BWP. In an example, SSG-0 may be the default SSG ofSSGs configured on the BWP, based on example embodiments described abovewith respect to FIG. 30 and/or FIG. 31 . Starting to monitor SSG-0 (orthe default SSG) until (or after) the wireless device finishes the PDCCHskipping for a time duration, even if a SSG switching timer expiresduring the time duration, may allow the wireless device to save powerconsumption for PDCCH monitoring. If the wireless device starts tomonitor SSG-0 when the SSG switching timer expires during the timeduration in which the wireless device is in PDCCH skipping, the wirelessdevice may increase power consumption for PDCCH monitoring by shorteningtime duration for PDCCH skipping. Example embodiments may improve powerconsumption of the wireless device and/or allow the base station and thewireless device to align regarding on which SSG the wireless deviceshould monitor when the wireless device is in PDCCH skipping and a SSGswitching timer expires.

As shown in FIG. 32 , the wireless device may receive, at a fourth slot(T3), a DCI (2^(nd) DCI) indicating SSG switching to SSG-2 (from SSG-0),e.g., when the wireless device monitors PDCCH on SSG-0. The wirelessdevice may switch PDCCH monitoring from SSG-0 to SSG-2. The wirelessdevice may start a SSG switching timer for SSG-2 in response toswitching to SSG-2. The SSG switching timer for SSG-2 may expire (e.g.,at a fifth slot, T4 when no DCI is received between T3 and T4). In anexample, T4 is not within a time duration for PDCCH skipping. Thewireless device does not receive PDCCH skipping indication for a timeduration including T4. In response to the SSG switching timer for SSG-2expiring, the wireless device may switch from SSG-2 to SSG-0 for PDCCHmonitoring. The wireless device may start to monitor PDCCH on SSG-0after T4.

Based on example embodiments of FIG. 32 , in response to a SSG switchingtimer expiring in a first slot and when PDCCH skipping is applied for atime duration (a number of slots) by a wireless device, the wirelessdevice may determine to start monitoring a default SSG (a SSG withsearch space group index 0) at a second slot determined based on thefirst slot and the last slot of the time duration. In response to thefirst slot occurring after the last slot of the time duration, thesecond slot is determined as a slot after the first slot. In response tothe first slot occurring before the last slot of the time duration, thesecond slot is determined as a slot after the last slot.

Based on example embodiments of FIG. 32 , a wireless device may delaySSG switching (to a default SSG), triggered by an expiry of a SSGswitching timer, until (or after) the wireless device finishes (orcompletes) PDCCH skipping for a time duration indicated by the basestation, if the SSG switching timer expires in a slot within the timeduration. The wireless device may switch SSG (to a default SSG),triggered by an expiry of a SSG switching timer, immediately after theexpiry the SSG switching timer, if the SSG switching timer expires in aslot not within a time duration in which the wireless device is in PDCCHskipping, or if the wireless device does not receive PDCCH skippingindication before the expiry of the SSG switching timer. Exampleembodiments may improve power consumption of the wireless device and/orallow the base station and the wireless device to align regarding onwhich SSG the wireless device should monitor when the wireless device isin PDCCH skipping and a SSG switching timer expires.

In existing technologies, a wireless device may receive a first DCIcomprising a PDCCH skipping indication indicating that the wirelessdevice skips PDCCH monitoring on a BWP for a time duration, e.g., basedon example embodiments of FIG. 29 . The wireless device may receive asecond DCI comprising a SSG indication indicating the wireless deviceswitches PDCCH monitoring from a first SSG to a second SSG on the BWP,e.g., based on example embodiments of FIG. 28A and/or FIG. 28B. Based onimplementing existing technologies, a wireless device receiving two DCIsindicating PDCCH skipping indication and SSG switching indication mayresult in increased power consumption of the wireless device, and/orresult in increased signaling transmission latency for the PDCCHskipping indication and SSG switching indication. There is a need toreduce signaling overhead for PDCCH skipping indication and SSGswitching indication and/or reduce power consumption of a wirelessdevice for receiving the PDCCH skipping indication and SSG switchingindication.

In an example embodiment, a base station may transmit, and/or a wirelessdevice may receive, a DCI comprising a first field indicating skippingPDCCH monitoring for a time duration and a second field indicating a SSGof a plurality of SSGs. The SSG may be used for PDCCH monitoring afterthe wireless device skips PDCCH monitoring for the time duration. Basedon the DCI, the wireless device may skip PDCCH monitoring for the timeduration. After the time duration expires, the wireless device mayswitch to a second SSG for PDCCH monitoring, wherein the second SSG isindicated by the DCI. Example embodiments, by indicating a time durationfor skipping PDCCH monitoring and a SSG for resuming PDCCH monitoringafter performing the PDCCH skipping, may result in reduced signalingoverhead of a DCI transmission. Therefore, a single DCI may be designedto avoid the possible misalignment between the skipping PDCCH operationand the SSG switching operation indicated across multiple DCIs,according to some embodiments. Example embodiments may enable the basestation to flexibly indicate a SSG for resuming PDCCH monitoring afterthe PDCCH skipping. Example embodiments may reduce power consumption ofa wireless device and/or reduce data transmission latency.

In an example embodiment, a base station may transmit, and/or a wirelessdevice may receive, a DCI comprising a DCI field indicating a timeduration for skipping PDCCH monitoring. The DCI may not comprise a SSGindex for SSG switching. The time duration, being set to the firstvalue, may indicate that the wireless device skip PDCCH monitoring forthe rest time period of a first time window associated with a first SSG.The first SSG may be a SSG on which the wireless device is monitoringPDCCH when the wireless device receives the DCI. The first time windowmay be running when the wireless device receives the DCI. Based on theDCI indicating PDCCH skipping and the time duration being set to thefirst value, the wireless device may skip PDCCH monitoring on the firstSSG for the rest time period of the first time window. The wirelessdevice may switch from the first SSG to a second SSG after the firsttime window expires. The second SSG may be configured by RRC messages,MAC CE(s), and/or DCIs. The wireless device may monitor PDCCH on thesecond SSG after the switching and/or when the first time windowexpires. Example embodiments may enable the base station to indicatethat the wireless device stops (or skips) PDCCH monitoring for a resttime period of a time duration associated with an SSG. Otherwise,indicating a length, of a duration of PDCCH skipping, equal to the resttime period (which may be variable depending on UE's state,configuration, a slot index of a current slot, etc.) of the timeduration, may increase DCI payload for a DCI, and/or increase powerconsumption of the wireless device. Example embodiments may reduce powerconsumption of the wireless device for receiving PDCCH skippingindication and SSG switching indication.

FIG. 33 shows an example embodiment of power saving operation with PDCCHskipping and SSS group switching. In an example, a base station maytransmit to a wireless device one or more RRC messages comprisingconfiguration parameters of a plurality of SSGs on a BWP of a cell. Theconfiguration parameters may be implemented based on example embodimentsdescribed above with respect to FIG. 27 , FIG. 30 and/or FIG. 31 .

As shown in FIG. 33 , the wireless device may monitor PDCCH according to(or on) a first SSG, of the plurality of SSGs, on the BWP. The first SSGmay be a default SSG configured by the one or more RRC messages. Thefirst SSG may be a SSG with group index equal to 0.

As shown in FIG. 33 , the wireless device may receive, during monitoringthe PDCCH on the first SSG, a first DCI (e.g., 1^(st) DCI) comprising afirst DCI field indicating skipping PDCCH monitoring for a first timewindow and a second DCI field indicating a second SSG to which thewireless device may switch from the first SSG after the first timewindow (or after skipping PDCCH monitoring for the first time window). Atime value of the first time window may be indicated in the first DCIand/or by the one or more RRC messages (e.g., based on exampleembodiments with respect to FIG. 37 ). The first DCI may be with a DCIformat based on example embodiments described above with respect to FIG.24 .

In an example, based on the first DCI field indicating skipping PDCCHmonitoring for the first time window, the wireless device may stopmonitoring PDCCH on the BWP (e.g., the first SSG, the second SSG, or oneor more of the plurality of SSGs configured on the BWP). The wirelessdevice may start the first time window with the initial time value.

In an example, the wireless device may switch from the first SSG to thesecond SSG (indicated by the first DCI) in response to the first timewindow expiring. The wireless device may start a second time windowassociated with the second SSG based on switching to the second SSG onthe BWP. A second time value for the second time window may beconfigured in the one or more RRC messages (e.g., based on exampleembodiments described above with respect to FIG. 30 ).

In an example, during the second time window being running and/ormonitoring the PDCCH on the second SSG on the BWP, the wireless devicemay receive a second DCI (e.g., 2^(nd) DCI) scheduling a TB via a PDSCH(or a PUSCH), the wireless device may receive the TB via the PDSCH (ortransmit the TB via the PUSCH). The wireless device may start (orrestart) the second time window with the initial time value in responseto receiving the second DCI.

In an example, in response to the second time window expiring, thewireless device may switch from the second SSG to the first SSG forPDCCH monitoring on the BWP.

In an example embodiment, when the wireless device is configured withDRX operation (e.g., based on example embodiments described above withrespect to FIG. 22A and/or FIG. 22B), example embodiments of FIG. 33 maybe applied in a time duration when the DRX operation is in active time(e.g., a DRX on duration timer is running, a DRX inactivity timer isrunning, DRX retransmission timers are running, a SR is sent on PUCCHand is pending, or a PDCCH indicating a new transmission addressed tothe C-RNTI of the MAC entity has not been received after successfulreception of a RAR for the Random Access Preamble not selected by theMAC entity among the contention-based Random Access Preamble). Applingthe embodiments of FIG. 33 in the DRX active time may comprisemonitoring PDCCH, receiving the one or more DCIs (1^(st) DCI, 2^(nd)DCI, etc.) in the DRX active time.

Based on example embodiments of FIG. 33 , a base station may transmit,and/or a wireless device may receive, a DCI, via a PDCCH of a BWP of afirst cell, comprising a first field indicating skipping PDCCHmonitoring on the first cell (or a second cell) for a time duration anda second field indicating a SSG of a plurality of SSGs on the firstcell. The SSG may be used for PDCCH monitoring after the wireless deviceskips PDCCH monitoring for the time duration. Based on the DCI, thewireless device may skip PDCCH monitoring on the first cell (or all BWPsof the first cell) for the time duration (e.g., the time durationstarting at a slot after receiving the DCI). After the time durationexpires, the wireless device may switch to a second SSG of the firstcell for PDCCH monitoring, wherein the second SSG is indicated by theDCI. Example embodiments, by indicating not only a time duration forskipping PDCCH monitoring but also a SSG for resuming PDCCH monitoringafter the PDCCH skipping, may reduce signaling overhead of a DCItransmission. Example embodiments may enable the base station toflexibly indicate a SSG for resuming PDCCH monitoring after the PDCCHskipping. Example embodiments may reduce power consumption of a wirelessdevice and/or reduce data transmission latency.

FIG. 34 shows an example embodiment of power saving operation with PDCCHskipping and SSS group switching. In an example, a base station maytransmit to a wireless device one or more RRC messages comprisingconfiguration parameters of a plurality of SSGs on a BWP of a cell. Theconfiguration parameters may be implemented based on example embodimentsdescribed above with respect to FIG. 27 , FIG. 30 , FIG. 31 , and/orFIG. 33 .

As shown in FIG. 34 , the wireless device may monitor PDCCH according to(or on) a first SSG, of the plurality of SSGs, on the BWP. The first SSGmay be a default SSG configured by the one or more RRC messages. Thefirst SSG may be a SSG with group index equal to 0.

A shown in FIG. 34 , the wireless device may receive, during monitoringthe PDCCH on the first SSG, a first DCI (e.g., 1^(st) DCI) comprising aSSG switching indication indicating switching from the first SSG to asecond SSG of the plurality of SSGs on the BWP. The first DCI maycomprise a SSG index indicating the second SSG to which the wirelessdevice switches PDCCH monitoring from the first SSG. The first DCI maybe with a DCI format based on example embodiments described above withrespect to FIG. 24 .

As shown in FIG. 34 , in response to receiving the SSG switchingindication in the first DCI, the wireless device may switch PDCCHmonitoring from the first SSG to the second SSG on the BWP. The wirelessdevice may start a first time window (or a first timer) based on a firsttimer value associated with the first time window. In an exampleembodiment, the first timer value may be indicated by the first DCIand/or the one or more RRC messages (e.g., based on example embodimentsof FIG. 30 and/or FIG. 37 ).

As shown in FIG. 34 , the wireless device may receive, during monitoringthe PDCCH on the second SSG, a second DCI (e.g., 2^(nd) DCI) comprisinga DCI field indicating skipping PDCCH monitoring for the rest timeperiod of the first window. The DCI field, being set to a first value,may indicate that the wireless device skips PDCCH monitoring on the BWPfor the rest time period of the first window, e.g., based on exampleembodiments of FIG. 35 , FIG. 36 and/or FIG. 37 which will be describedlater. The first DCI may be with a DCI format based on exampleembodiments described above with respect to FIG. 24 .

In an example, based on the DCI field, of the second DCI, indicatingskipping PDCCH monitoring for the first time window, the wireless devicemay stop monitoring PDCCH on the BWP (e.g., the first SSG, the secondSSG, or one or more of the plurality of SSGs configured on the BWP) forthe rest time period of the first time window. The wireless device maykeep running the first time window and stop monitoring PDCCH on thesecond SSG during the first time window being running.

In an example, the wireless device may switch from the second SSG to athird SSG of the plurality of SSGs on the BWP in response to the firsttime window expiring. The third SSG may be the first SSG. The third SSGmay be configured as a dedicated SSG for resuming PDCCH monitoring onthe BWP after skipping PDCCH for a time duration, of the plurality ofSSGs based on the one or more RRC messages. The wireless device maystart a second time window associated with the third SSG based onswitching to the third SSG on the BWP. A second time value for thesecond time window may be configured in the one or more RRC messages(e.g., based on example embodiments described above with respect to FIG.30 ).

In an example embodiment, when the wireless device is configured withDRX operation (e.g., based on example embodiments described above withrespect to FIG. 22A and/or FIG. 22B), example embodiments of FIG. 34 maybe applied in a time duration when the DRX operation is in active time(e.g., a DRX on duration timer is running, a DRX inactivity timer isrunning, DRX retransmission timers are running, a SR is sent on PUCCHand is pending, or a PDCCH indicating a new transmission addressed tothe C-RNTI of the MAC entity has not been received after successfulreception of a RAR for the Random Access Preamble not selected by theMAC entity among the contention-based Random Access Preamble). Applingthe embodiments of FIG. 34 in the DRX active time may comprisemonitoring PDCCH, receiving the one or more DCIs (1^(st) DCI, 2^(nd)DCI, 3^(rd) DCI, etc.) in the DRX active time.

Based on example embodiments of FIG. 34 , a base station may transmit,and/or a wireless device may receive, configuration parameters (e.g.,via RRC messages) indicating a dedicated SSG, of a plurality of SSGs ona BWP, for resuming PDCCH monitoring after the wireless device skipsPDCCH for a time duration. The wireless device, based on a DCI field ofa DCI, via a PDCCH of a BWP of a first cell, being set to a first (e.g.,predefined, non-numerical, fixed, etc.) value, may determine that thewireless may skip PDCCH monitoring during the rest time period of a timewindow associated with a current SSG on which the wireless device ismonitoring. The wireless device, after skipping PDCCH monitoring duringthe rest time period of the time window, may switch from a first SSG tothe dedicated SSG for PDCCH monitoring on the BWP. Example embodimentsmay enable the base station, by setting a PDCCH skipping time durationfield to a (predefined, or fixed) value, to indicate that the wirelessdevice skips PDCCH monitoring for a rest time period of a time windowassociated with an SSG. Example embodiments may reduce signalingoverhead for time duration indication for PDCCH skipping.

FIG. 35 shows an example flowchart of a method for achieving powersaving based on PDCCH skipping and SSS group switching, according tosome embodiments. In an example, a base station may transmit to awireless device one or more RRC messages comprising configurationparameters of a plurality of SSGs on a BWP of a cell. The configurationparameters may be implemented based on example embodiments describedabove with respect to FIG. 27 , FIG. 30 , FIG. 31 , FIG. 32 , FIG. 33 ,and/or FIG. 34 .

As shown in FIG. 35 , the wireless device may monitor PDCCH according to(or on) a first SSG (e.g., 1^(st) SSG), of the plurality of SSGs, on theBWP. The first SSG may be a default SSG configured by the one or moreRRC messages. The first SSG may be a SSG with group index equal to 0.The wireless device may start a first time window associated with thefirst SSG. The first time window may be implemented based on exampleembodiments described above with respect to FIG. 30 , FIG. 31 , FIG. 32, FIG. 33 , and/or FIG. 34 .

A shown in FIG. 35 , the wireless device may receive, during monitoringthe PDCCH on the first SSG, a DCI comprising a time value associatedwith a second time window for skipping PDCCH monitoring on the BWP. TheDCI may be with a DCI format based on example embodiments describedabove with respect to FIG. 24 .

As shown in FIG. 35 , the wireless device may determine whether the timevalue of the DCI is set to a first value (e.g., a predefined, or a fixedvalue known to both the base station and the wireless device).

In response to the time value being set to the first value, the wirelessdevice may determine to skip PDCCH monitoring for the rest time periodof the first time window and switch to a second SSG after the rest timeperiod of the first time window. The wireless device may skip PDCCHmonitoring on the first SSG for the rest time period of the first timewindow. The wireless device may switch from the first SSG to a secondSSG after the first time window (or a timer associated with the firsttime window expires). The wireless device may monitor PDCCH on thesecond SSG after the switching.

In response to the time value not being set to the first value, thewireless device may determine to skip PDCCH monitoring on the first SSGfor a second time window indicated by the time value and resume PDCCHmonitoring on the first SSG (e.g., without switching to a second SSG)after the second time window (or when a timer associated with the secondtime window expires). Based on the determining, the wireless device mayskip PDCCH monitoring on the first SSG during the second time window.After the second time window, the wireless device may maintain on thefirst SSG (e.g., without switching to a second SSG). After the secondtime window, the wireless device may monitor the PDCCH on the first SSG(when the first time window is running).

FIG. 36 shows an example embodiment of a power saving operation withPDCCH skipping and SSS group switching. In an example, a wireless devicemay monitor a PDCCH on a first SSG (e.g., 1^(st) SSG), of a plurality ofSSGs on a BWP. The wireless device may start a first time window, (e.g.,associated with the first SSG), with a time duration.

In an example, during monitoring the PDCCH on the first SSG, thewireless device may receive a DCI indicating a PDCCH skipping. The DCImay comprise a PDCCH skipping indication field indicating a timeduration for the PDCCH skipping. The wireless device may determine toskip PDCCH monitoring on the first SSG for the rest time duration/periodof the first time window in response to the PDCCH skipping indicationfield being set to a first value. Based on the determining, the wirelessdevice may skip PDCCH monitoring on the first SSG for the rest timeduration of the first time window.

In an example, the wireless device may switch to a second SSG, of theplurality of SSGs, in response to the first time window expiring. Thesecond SSG may be configured by the base station. The DCI may notcomprise a SSG index indicating the second SSG. Based on the switchingto the second SSG, the wireless device may start monitoring PDCCH on thesecond SSG.

FIG. 37 shows an example embodiment of PDCCH skipping durationindication for power saving based on PDCCH skipping and SSG switching.In an example, a base station may transmit to a wireless device one ormore RRC messages comprising configuration parameters of PDCCH on a BWP.The configuration parameters may comprise a plurality of time values(e.g., a list of time values with orders) for PDCCH skipping on the BWP.The plurality of time values may comprise one or more first values(e.g., 1, 2, 3, any integer greater than 1) indicating that the wirelessdevice skips PDCCH monitoring for a number of slots, wherein the numberis, indicated by the PDCCH skipping duration indication field, one ofthe one or more first values. The plurality of time values may comprisea second value (e.g., zero) indicating that the wireless device does notskip PDCCH monitoring on the BWP in response to receiving a DCIcomprising a PDCCH skipping duration indication field indicating thefirst value. The plurality of time values may comprise a second value(e.g., a first non-numerical value, or a first predefined value)indicating that the wireless device skips PDCCH monitoring for a DRX onduration of a DRX cycle. The plurality of time values may comprise athird value (e.g., a second non-numerical value, or a second predefinedvalue) indicating that the wireless device skips PDCCH monitoring forthe rest time duration of a time window associated with an SSG. Thethird value may be different from the second value.

In an example, a wireless device may receive a DCI comprising the PDCCHskipping duration indication field. The PDCCH skipping durationindication field may indicate one of the plurality of time values forPDCCH skipping on the BWP. In an example, in response to the PDCCHskipping duration indication field being set to a first value (e.g.,000, when the field is configured with 3 bits), the wireless device mayskip PDCCH monitoring on the BWP for a first number of slots, the firstnumber corresponding to a first value of the plurality of time valuesconfigured by the one or more RRC messages. In response to the firstvalue being zero, the wireless may maintain PDCCH monitoring (e.g., bynot applying the PDCCH skipping) on the BWP. In response to the PDCCHskipping duration indication field being set to a second value (e.g.,001), the wireless device may skip PDCCH monitoring on the BWP for asecond number of slots, the second number corresponding to a secondvalue of the plurality of time values configured by the one or more RRCmessages, etc.

In an example, in response to the PDCCH skipping duration indicationfield being set to a seventh value (e.g., 110) and a correspondingseventh value of the plurality of time values being set to a firstpredefined value, the wireless device may skip PDCCH monitoring for aDRX on duration (or rest time of the DRX on duration if the DRX onduration is started). In response to the PDCCH skipping durationindication field being set to an eighth value (e.g., 111) and acorresponding seventh value of the plurality of time values being set toa second predefined value, the wireless device may skip PDCCH monitoringfor a rest time period of a time window associated with a SSG on whichthe wireless device is monitoring before receiving the DCI, etc.

Similarly, the PDCCH skipping duration indication field may beconfigured with a length of 1, 2 bits, or more than 3 bits. Theembodiments described above may be extended for a skipping durationindication field with a bit length different for 3 bits. In an example,in response to a time value associated with PDCCH skipping operationbeing set to a first predefined value (e.g., based on RRC messagesand/or DCI), the wireless device may skip PDCCH monitoring for a DRX onduration (or rest time of the DRX on duration if the DRX on duration isstarted). In response to a time value associated with PDCCH skippingoperation being set to a second predefined value (e.g., based on RRCmessages and/or DCI), the wireless device may skip PDCCH monitoring fora rest time period of a time window associated with a SSG on which thewireless device is monitoring before receiving the DCI, etc.

In existing technologies, a wireless device may receive a first DCIcomprising a PDCCH skipping indication indicating that the wirelessdevice skips PDCCH monitoring on a BWP for a time duration on a firstcell, e.g., based on example embodiments of FIG. 29 . The wirelessdevice may receive a second DCI, via a second cell, comprising a SSGindication indicating the wireless device switches PDCCH monitoring froma first SSG to a second SSG on the BWP, e.g., based on exampleembodiments of FIG. 28A and/or FIG. 28B. Based on implementing existingtechnologies, in response to receiving the second DCI after receivingthe first DCI, the wireless device may have difficulties in determiningthe wireless device behavior regarding the PDCCH skipping operation andthe SSG switching operation. In an example, the wireless device may havedifficulties in determining: whether the wireless device should disableor maintain the PDCCH skipping operation indicated by the first DCI;whether the wireless device should stop or keep running a first timewindow associated with the PDCCH skipping operation; when the wirelessdevice should start monitoring a second SSG; when the wireless deviceshould start a second time window associated with the second SSG, etc.There is a need to design the wireless device behavior and align thewireless device behavior with the base station when the SSG switchingoperation is received after a PDCCH skipping indication. Exampleembodiments may improve power consumption of a wireless device and/orreduce signaling transmission latency.

FIG. 38 shows an example embodiment of PDCCH skipping and SSG switchingbased power saving operation. In an example, a base station may transmitto a wireless device one or more RRC messages comprising configurationparameters of a plurality of search space groups (SSGs) on a BWP of afirst cell. The configuration parameters may be implemented based onexample embodiments described above with respect to FIG. 27 and/or FIG.30 .

As shown in FIG. 38 , the wireless device may monitor PDCCH according to(or on) a first SSG, of the plurality of SSGs, on the BWP. The wirelessdevice may receive, during monitoring the PDCCH on the first SSG, afirst DCI (e.g., 1^(st) DCI) comprising a PDCCH skipping indicationfield. The PDCCH skipping indication field may indicate a time durationduring which the wireless device stops PDCCH monitoring on the BWP,wherein the wireless device maintains the BWP in active state. In anexample, when configured with DRX operation (e.g., based on exampleembodiments described above with respect to FIG. 22A and/or FIG. 22B),the wireless device may receive the first DCI in a DRX on duration of aDRX cycle. The PDCCH skipping indication field may be implemented basedon example embodiments described above with FIG. 37 .

As shown in FIG. 38 , in response to receiving the PDCCH skippingindication field indicating the time duration for the PDCCH skipping,the wireless device may stop monitoring PDCCH on the BWP (e.g., thefirst SSG, or one or more SSG of the plurality of SSGs) of the firstcell. The wireless device may start a first time window (e.g., 1^(st)time window) or start a first timer based on the time duration.

As shown in FIG. 38 , the wireless device may receive a second DCI(e.g., 2^(nd) DCI) comprising a SSG switching indication (or flag)indicating switching from the first SSG to a second SSG of the pluralityof SSGs of the BWP of the first cell. The wireless device may receivethe second DCI via a second cell (e.g., PCell, a SCell, etc.) on whichthe wireless device is monitoring PDCCH. The wireless device may receivethe second DCI in a time instance when the wireless device is in thefirst time window and the wireless device stops monitoring PDCCH on thefirst cell. The SSG switching indication may indicate a SSG indexidentifying the second SSG. The SSG switching indication may be a flagindicating maintaining on the first SSG when set to a first value and/orindicating switching from the first SSG to the second SSG when set to asecond value. A second time duration (or a second timer) may beindicated (e.g., by the SSG switching indication of the second DCIand/or by the SSG configuration parameters of the RRC messages) for thesecond SSG. When switching to the second SSG, the wireless device maymonitor PDCCH on the second SSG with the second time duration. After thesecond time duration, the wireless device may stop monitoring the secondSSG (or switch to the first SSG, or another SSG of the plurality ofSSGs) on the BWP.

In an example embodiment, in response to receiving the SSG switchingindication from the second cell (e.g., during the first time windowbeing running), the wireless device may switch from the first SSG to thesecond SSG on the BWP of the first cell. The wireless device may stopthe first time window associated with PDCCH skipping in response toreceiving the SSG switching indication from the second cell. Thewireless device may start the second time duration (if configured)associated with the second SSG. The wireless device may determine thatstarting the second time duration (automatically) disables (or stops)the first time window. The wireless device may determine that the secondDCI indicating the SSG switching (automatically) disables the first DCIindicating the PDCCH skipping, e.g., when the wireless device isapplying the PDCCH skipping on the BWP and the wireless device receivesthe SSG switching indication from the second cell. The wireless devicemay start monitoring PDCCH on the second SSG based on switching from thefirst SSG to the second SSG. Stopping the first time window in responseto receiving a SSG switching indication may enable the wireless deviceto monitor PDCCH for a second SSG right after switching to the secondSSG based on the SSG switching indication, e.g., without waiting untilan expiry of the first time window. Example embodiments may improve datatransmission latency.

In an example, during the second time window, the wireless device mayreceive a DCI (not shown in FIG. 38 ) based on monitoring the PDCCH onthe second SSG on the BWP of the first cell. The wireless device maytransmit a TB or receive a TB based on the DCI indicating uplink grantor indicating downlink assignment.

As shown in FIG. 38 , when the second time window expires, the wirelessdevice may switch from the second SSG to another SSG (e.g., the firstSSG, or a third SSG of the plurality of SSGs). The wireless device maymonitor the PDCCH on the SSG on the BWP of the first cell, after theswitching. The wireless device may receive a third DCI scheduling a TBvia a PDSCH. The wireless device may receive the TB via the PDSCH basedon the third DCI.

In an example embodiment, in response to receiving the SSG switchingindication from the second cell (e.g., during the first time windowbeing running), the wireless device may switch from the first SSG to thesecond SSG on the BWP of the first cell. The wireless device may keeprunning the first time window associated with PDCCH skipping. During thefirst time window being running, the wireless device may stop monitoringPDCCH on the BWP of the first cell, e.g., even after the wireless deviceswitches from the first SSG to the second SSG. During the first timewindow being running, the wireless device may not start a second timewindow associated with the second SSG, even the wireless device hasswitched to the second SSG.

Based on the example embodiment, the wireless device may not disable thePDCCH skipping after receiving a SSG switching indication. Not disablingthe PDCCH skipping may comprise keeping running the first time windowassociated with the PDCCH skipping and/or stopping PDCCH monitoring onthe BWP of the first cell. The wireless device may start monitoring asecond SSG and start a second time window associated with the second SSGin response to the first time window expiring, (e.g., not right afterreceiving the SSG switching indication).

In an example embodiment, the wireless device may start the second timewindow associated with the second SSG in response to the first timewindow expiring (or after the first time window during which thewireless device stops PDCCH skipping on the BWP of the first cell). Thewireless device may start PDCCH monitoring on the second SSG in responseto the first time window expiring and/or starting the second timewindow. During the PDCCH monitoring on the second SSG, the wirelessdevice may receive a DCI scheduling a TB via a PDSCH. The wirelessdevice may receive the TB via the PDSCH based on the DCI.

In an example embodiment, when the wireless device is configured withDRX operation (e.g., based on example embodiments described above withrespect to FIG. 22A and/or FIG. 22B), example embodiments of FIG. 38 maybe applied in a time duration when the DRX operation is in active time(e.g., a DRX on duration timer is running, a DRX inactivity timer isrunning, DRX retransmission timers are running, a SR is sent on PUCCHand is pending, or a PDCCH indicating a new transmission addressed tothe C-RNTI of the MAC entity has not been received after successfulreception of a RAR for the Random Access Preamble not selected by theMAC entity among the contention-based Random Access Preamble). Applingthe embodiments of FIG. 38 in the DRX active time may comprisemonitoring PDCCH, receiving the one or more DCIs (1^(st) DCI, 2^(nd)DCI, 3^(rd) DCI, etc.) in the DRX active time.

Based on example embodiments, the wireless device may keep running atime window associated with PDCCH skipping on a cell in response toreceiving a DCI indicating switching from a first SSG to a second SSG onthe cell. The wireless device may start monitoring PDCCH on the secondSSG after the time window associated with the PDCCH skipping expires.The wireless device may not start monitoring the PDCCH on the second SSGduring the time window being running, e.g., after the wireless deviceswitches to the second SSG. Example embodiments may reduce powerconsumption of the wireless device and/or align with the base station ona length of a duration on which the wireless device monitors PDCCH onthe second SSG. Example embodiments, by alignment of the length of theduration for PDCCH monitoring on the second SSG, may reduce latency ofdata/signaling transmission.

In an example embodiment, during a time window in which the wirelessdevice stops monitoring PDCCH on a cell, the wireless device may receivea DCI (via a second cell) comprising a SSG switching indicationindicating switching from a first SSG to a second SSG on the cell. Thewireless device may determine whether to stop or keep running the timewindow associated with PDCCH skipping on the cell in response toreceiving the DCI. In an example, the wireless device may keep runningthe time window in response to the second SSG being a dormant SSG (e.g.,without search spaces configured). During the time window being running,the wireless device may stop monitoring PDCCH on the cell. In anexample, the wireless device may stop the time window in response to thesecond SSG being a non-dormant SSG. In response to stopping the timewindow, the wireless device may switch PDCCH monitoring from the firstSSG to the second SSG. The wireless device may monitor the PDCCH on thesecond SSG based on the SSG switching.

In an example embodiment, a wireless device may receive a first DCIindicating a first search space group, of a plurality of search spacegroups, for PDCCH monitoring on a BWP. The wireless device, in responseto receiving the first DCI, may monitor the PDCCH via the first searchspace group and start a first time window. The wireless device mayreceive a second DCI comprising a PDCCH skipping indication. Thewireless device, in response to receiving the second DCI, may stop thePDCCH monitoring on the BWP, stop the first time window and start asecond time window. In response to an expiry of the second time window,the wireless device may monitor the PDCCH via the first search spacegroup and start (or restart) the first time window. The wireless devicemay switch, in response to an expiry of the first time window, PDCCHmonitoring from the first search space group to a second search spacegroup of the plurality of search space groups.

According to an example embodiment, a wireless device may receive afirst DCI indicating a first search space group, of a plurality ofsearch space groups, for PDCCH monitoring on a BWP. The wireless devicemay start a first time window based on the first DCI. The wirelessdevice, during the first time window, may monitor the PDCCH via thefirst search space group. The wireless device may receive a second DCIindicating skipping PDCCH monitoring on the BWP. based on the secondDCI, the wireless device may stop the first time window and start asecond time window. The wireless device may stop PDCCH monitoring on theplurality of search space groups during the second time window.

According to an example embodiment, the wireless device, in response toan expiry of the second time window, may start (or restart) the firsttime window. The wireless device may monitor the PDCCH via the firstsearch space group during the first time window (or when a timerassociated with the first time window is running). The wireless devicemay switch, in response to an expiry of the first time window, the PDCCHmonitoring from the first search space group to a second search spacegroup of the plurality of search space groups.

According to an example embodiment, the first DCI may indicate a firsttimer value for the first time window. The second DCI may indicate asecond timer value for the second time window.

According to an example embodiment, the wireless device may receive oneor more RRC messages comprising configuration parameters of theplurality of search space groups on the BWP of a cell, wherein theplurality of search space groups comprise the first search space groupand the second search space group. The configuration parameters mayindicate a timer value for the first time window. Each search spacegroup, of the plurality of search space groups, may comprise one or moresearch space with a same search space group index.

According to an example embodiment, the configuration parameters maycomprise first configuration parameters for each search space of the oneor more search space, wherein the first configuration parameterscomprise a search space indicator identifying the search space, acontrol resource set indicator indicating a control resource setassociated with the search space, a monitoring slot periodicity andoffset parameter for PDCCH monitoring on the search space, a timeduration, a monitoring symbols within slot indicator, a number ofcandidates, a search space type (e.g., common search space type,UE-specific search space type), and/or one or more SSG group indexesassociated with the search space.

According to an example embodiment, the control resource set may beconfigured with second configuration parameters comprising frequencydomain resource configuration parameters, a duration value, a controlchannel element to resource element group mapping type indication,and/or a control resource set pool index.

According to an example embodiment, the second DCI does not indicate asearch space group switching from the first search space group to thesecond search space group.

According to an example embodiment, the BWP is in active state on thecell. The second DCI does not indicate an active BWP switching. Thewireless device may maintain the BWP in active state based on receivingthe second DCI.

According to an example embodiment, the wireless device receives one ormore RRC messages comprising configuration parameters of the cell,wherein the cell comprises a plurality of BWPs comprising the BWP. Thewireless device may activate the BWP, of the plurality of BWPs, based onreceiving an activation command indicating an activation of the BWP. Theactivation command may comprise at least one of: a third DCI indicatingan active BWP switching to the BWP part from a second BWP of the cell, aMAC CE indicating an activation of the cell and RRC message comprising acell state indication, for the cell, indicating an active state.

According to an example embodiment, the first DCI comprises at least oneof: a group common DCI addressed to a plurality of wireless devicescomprising the wireless device and a wireless device dedicated DCIaddressed to the wireless device. The second DCI comprises at least oneof: a group common DCI addressed to a plurality of wireless devicescomprising the wireless device and a wireless device dedicated DCIaddressed to the wireless device.

According to an example embodiment, the first DCI may indicate PDCCHmonitoring switching from a third search space group, of the pluralityof search space groups, to the first search space group on the BWP.

According to an example embodiment, the first DCI and the second DCI arewith a same DCI format comprising a DCI field. The DCI field, of thefirst DCI, being set to a first value indicates that the first DCIindicates a SSG switching. The DCI field, of the second DCI, being setto a second value indicates that the second DCI indicates a PDCCHmonitoring skipping.

According to an example embodiment, the switching the PDCCH monitoringfrom the first search space group to the second search space groupcomprises stopping monitoring the PDCCH on the first search space groupand starting monitoring the PDCCH on the second search space group.

In an example embodiment, a wireless device may receive a first DCIindicating a first search space group (SSG), of a plurality of SSGs, forPDCCH monitoring on a BWP. The wireless device may monitor, based on thefirst DCI, the PDCCH via the first SSG. The wireless device may receivea second DCI. The second DCI may indicate: PDCCH skipping on thebandwidth part, and a second SSG, of the plurality of SSGs, for PDCCHmonitoring. Based on the second DCI, the wireless device may stop PDCCHmonitoring on the plurality of SSGs during a second time window. Thewireless device may switch to the second SSG for PDCCH monitoring inresponse to an expiry of the second time window. The second DCI maycomprise a first DCI field indicating the PDCCH skipping and comprise asecond DCI field indicating the second SSG.

According to an example embodiment, a wireless device may monitor aPDCCH via a first SSG on a BWP. The wireless device may receive, duringthe monitoring, a downlink control information indicating: PDCCHskipping on the BWP and a second SSG for PDCCH monitoring. The wirelessdevice may stop PDCCH monitoring on the first SSG during a time window.The wireless device may switch to the second SSG for PDCCH monitoring inresponse to an expiry of the time window.

According to an example embodiment, the DCI may indicate a time valuefor the time window.

According to an example embodiment, the wireless device may receive oneor more RRC messages comprising configuration parameters of theplurality of SSGs on the BWP of a cell, wherein the plurality of SSGscomprise the first SSG and the second SSG. The configuration parametersmay indicate a time value for a second time window. The wireless devicemay start the second time window in response to switching to the secondSSG. The wireless device may monitor the PDCCH on the second SSG duringthe second time window. The wireless device may switch to the first SSGfor PDCCH monitoring in response to an expiry of the second time window.

In an example embodiment, a wireless device may receive configurationparameters of a plurality of SSGs on a BWP. The wireless device maymonitor, during a first time window, a PDCCH via a first SSG on the BWP.The wireless device may receive, during the monitoring, a DCI indicatinga time vale for skipping monitoring the PDCCH. In response to the timevalue being set to a first value, the wireless device may stopmonitoring the PDCCH on the first SSG when the first time window isrunning and may switch to a second SSG for PDCCH monitoring in responseto an expiry of the first time window.

According to an example embodiment, the wireless device may start asecond time window based on a second value in response to the time valuebeing set to the second value. The wireless device may stop monitoringthe PDCCH on the first SSG during the second time window. The wirelessdevice may switch to the first SSG for PDCCH monitoring in response toan expiry of the second time window.

According to an example embodiment, the configuration parameters mayindicate the second SSG for the PDCCH monitoring after the expiry of thefirst time window. The second SSG may be configured independently and/orseparately from a default SSG of the plurality of SSGs.

According to an example embodiment, the second SSG may be a default SSGof the plurality of SSGs, wherein the default SSG is a SSG via which thewireless device monitors the PDCCH in response to at least one of: (re-)configuration of the cell, activation of the cell, switching an activeBWP to the BWP, and/or starting a DRX timer (e.g., DRX on durationtimer) of a DRX configuration.

According to an example embodiment, the wireless device may stop thefirst time window in response to receiving the DCI.

What is claimed is:
 1. A wireless device comprising: one or moreprocessors; and memory storing instructions that, when executed by theone or more processors, cause the wireless device to: in response to atimer, for switching physical downlink control channel (PDCCH)monitoring from a first search space group (SSG) of a bandwidth part(BWP) to a second SSG of the BWP, expiring in a slot within a timeduration for skipping PDCCH monitoring on the BWP, start to monitorPDCCH on the second SSG no earlier than an expiration of the timeduration.
 2. The wireless device of claim 1, wherein the instructionsfurther cause the wireless device to start the timer for the first SSG,of SSGs, on the BWP, wherein the timer is started: based on receiving afirst downlink control information (DCI) via the first SSG; and with atimer value associated with the first SSG.
 3. The wireless device ofclaim 1, wherein the instructions further cause the wireless device toreceive, based on monitoring the PDCCH on the first SSG and while thetimer is running, a first downlink control information (DCI) indicatingto skip the PDCCH monitoring on the BWP for the time duration.
 4. Thewireless device of claim 1, wherein the timer for SSG switching expiresin a first slot, and the time duration for skipping PDCCH monitoringends in a second slot after the first slot, and wherein the starting tomonitor the PDCCH on the second SSG no earlier than the expiration ofthe time duration comprises starting to monitor the PDCCH on the secondSSG after the second slot.
 5. The wireless device of claim 1, whereinthe instructions further cause the wireless device to receive one ormore radio resource control (RRC) messages comprising configurationparameters of the BWP, indicating: a plurality of search spaces, of theBWP, comprising the first SSG and the second SSG; a timer value for thetimer for SSG switching to the second SSG; and the time duration forskipping PDCCH monitoring on the BWP.
 6. The wireless device of claim 1,wherein the instructions further cause the wireless device to start thetimer, based on the timer value associated with the first SSG, inresponse to switching to the first SSG for PDCCH monitoring on the BWP.7. The wireless device of claim 1, wherein an index of the second SSG iszero.
 8. A base station comprising: one or more processors; and memorystoring instructions that, when executed by the one or more processors,cause the base station to: in response to a timer, for switchingphysical downlink control channel (PDCCH) monitoring from a first searchspace group (SSG) of a bandwidth part (BWP) to a second SSG of the BWP,expiring in a slot within a time duration for skipping PDCCH monitoringon the BWP, transmit to a wireless device, the PDCCH on the second SSGno earlier than an expiration of the time duration.
 9. The base stationof claim 8, wherein the instructions further cause the base station tostart the timer for the first SSG, of SSGs, on the BWP, wherein thetimer is started, based on transmitting a first downlink controlinformation (DCI) via the first SSG and with a timer value associatedwith the first SSG.
 10. The base station of claim 8, wherein theinstructions further cause the base station to transmit to the wirelessdevice, while the timer is running, a first downlink control information(DCI) indicating to skip the PDCCH monitoring on the BWP for the timeduration.
 11. The base station of claim 8, wherein the timer for SSGswitching expires in a first slot, and the time duration for skippingPDCCH monitoring ends in a second slot after the first slot, and whereinthe transmitting the PDCCH on the second SSG no earlier than theexpiration of the time duration comprises starting to transmit the PDCCHon the second SSG after the second slot.
 12. The base station of claim8, wherein the instructions further cause the base station to transmitto the wireless device, one or more radio resource control (RRC)messages comprising configuration parameters of the BWP, indicating: aplurality of search spaces, of the BWP, comprising the first SSG and thesecond SSG; a timer value for the timer for SSG switching to the secondSSG; and the time duration for skipping PDCCH monitoring on the BWP. 13.The base station of claim 8, wherein the instructions further cause thebase station to start the timer, based on the timer value associatedwith the first SSG, in response to switching to the first SSG for PDCCHmonitoring on the BWP.
 14. A non-transitory computer-readable mediumcomprising instructions that, when executed by one or more processors ofa wireless device, cause the wireless device to: in response to a timer,for switching physical downlink control channel (PDCCH) monitoring froma first search space group (SSG) of a bandwidth part (BWP) to a secondSSG of the BWP, expiring in a slot within a time duration for skippingPDCCH monitoring on the BWP, start to monitor PDCCH on the second SSG noearlier than an expiration of the time duration.
 15. The non-transitorycomputer-readable medium of claim 14, wherein the instructions furthercause the wireless device to start the timer for the first SSG, of SSGs,on the BWP, wherein the timer is started: based on receiving a firstdownlink control information (DCI) via the first SSG; and with a timervalue associated with the first SSG.
 16. The non-transitorycomputer-readable medium of claim 14, wherein the instructions furthercause the wireless device to receive, based on monitoring the PDCCH onthe first SSG and while the timer is running, a first downlink controlinformation (DCI) indicating to skip the PDCCH monitoring on the BWP forthe time duration.
 17. The non-transitory computer-readable medium ofclaim 14, wherein the timer for SSG switching expires in a first slot,and the time duration for skipping PDCCH monitoring ends in a secondslot after the first slot, and wherein the starting to monitor the PDCCHon the second SSG no earlier than the expiration of the time durationcomprises starting to monitor the PDCCH on the second SSG after thesecond slot.
 18. The non-transitory computer-readable medium of claim14, wherein the instructions further cause the wireless device toreceive one or more radio resource control (RRC) messages comprisingconfiguration parameters of the BWP, indicating: a plurality of searchspaces, of the BWP, comprising the first SSG and the second SSG; a timervalue for the timer for SSG switching to the second SSG; and the timeduration for skipping PDCCH monitoring on the BWP.
 19. Thenon-transitory computer-readable medium of claim 14, wherein theinstructions further cause the wireless device to start the timer, basedon the timer value associated with the first SSG, in response toswitching to the first SSG for PDCCH monitoring on the BWP.
 20. Thenon-transitory computer-readable medium of claim 14, wherein an index ofthe second SSG is zero.